Clutch Problem #2.

January 26, 2008 2:03 PM

Mechanic Question: Even though I just changed the clutch, it still won't start. The starter runs, the flywheel and some of the transmission is turning (I can hear it loud and clear), but it won't fire; it just spins.

We're talking, by the way, about a 1996 Volkswagon Jetta, manual five-speed.

Thanks to all who helped with my last question. So: I've installed a new clutch, clean and everything, putting a small amount of high-temp grease on the spindle as I was doing so, like the manual says, and cleaned off the flywheel, too. I reassembled everything, put the transaxle back on, and reattached the driveaxles and the wheels and everything. And now it still won't start.

What's happening now is very similar to what was happening before I replaced the clutch. (That worries me somewhat.) I'll depress the clutch pedal and turn the key, and I can hear the starter motor turning the gears ("whirrrr!") but it won't turn over ("chuh-chuh-chuh-chuh") and fire ("vroom!"). As I hold the key turned, it keeps whirring, but slowly starts to engage... it starts chugging a little... and then the chugging subsides again and it just whirs. This process repeats, and it goes in and out of starting to turn over. If I let out the clutch while I'm turning the key and I have it in first, the car will start to move ever so slightly forward, and then stop moving; but it won't kick forward, like it ought to. I've tried push-starting, and, of course, that's useless.

So does anybody know what's going on here? One thing I can say: I left it for a week where it was after having this happen last week, and then today when I tried to turn it on it almost turned over on the first time. That's not really something I can experiment with, unfortunately, if I want to get this car fixed within the next month.

posted by koeselitz to travel & transportation (85 answers total)

I'm confused. The clutch doesn't have anything to do with making the engine run, it's just one of the parts that connects the engine to the wheels so that the engine (when running) can cause the wheels to turn. What you're describing sounds like a problem that has nothing whatsoever to do with the clutch. When a clutch goes bad the engine still runs fine, but the car doesn't move.

My mechanical experience is strictly shade tree, not professional, but I think the most basic questions to ask are, is the engine getting gas, air and spark? An air restriction is unlikely to keep this thing from starting, so narrow it to gas and spark. Take out a spark plug after one of these non-starting sessions. Is it wet and does it smell like gas? No? Then you have a fuel delivery problem. If it is wet then the problem may be ignition-related. Dry the gas off of the spark plug, insert its back end into the plug wire and ground the plug while someone else turns the key. Check to see whether the plug is sparking rhythmically as the engine turns over. No? Then you've got an ignition problem.

Boil it down to those beginning questions; is the gas getting into the cylinder and, if it is, why isn't it being lit on fire? As you kick these ideas around, clarify your terminology: if you hear any chuh-chuh-chuh at all then your engine IS turning over. It may not be firing or starting, but all turning over means is that the engine is being spun by the starter motor.
posted by jon1270 at 2:34 PM on January 26, 2008

You seem to know a fair amount about cars. I mean, hey, you just replaced a clutch. Have you double-checked all the basics, though?

1) Did you try jump-starting it while doing this?
2) How much gas is there in your car?
3) Are you pressing down on the clutch pedal (I know this one sounds phenomenally stupid, but after I finally got my car fixed this summer, I had become accustomed to driving automatics and forgot that the clutch pedal is your friend.)
4) You check the spark plug connections?
posted by Happydaz at 2:39 PM on January 26, 2008

1: You don't need to touch the clutch pedal to start the car. Put it in neutral and it is essentially teh same thing from your perspective.

2: Please god, don't tell me this is the reason you went through all that heartache with your clutch. The failure to start has exactly nothing to do with the clutch. If that really was teh reason, you have wasted an awful lot of time and money...

3: This sounds more like a starter issue to me, but without more detail on the chugging and whirring, it's impossible to say.

When you turn the key to 'start', does the engine physically turn all the time you have the key held in the start position? Does it turn at a constant speed? Get someone to turn the key and hold it there and watch the crankshaft/belts at the lefthand side (as you look in the engine bay) of the engine. If the noise doesn't affect how fast the engine turns, and it turns reasonably fast and smoothly, then there is no starter issue.

By "Whirr" do you mean a relatively high pitched, starter only kind of noise? If so, the starter is not engaging and replacing the starter will sort this out (check, first of all, that it has good electrical connections). It sounds to me like the starter is not engaging in the flywheel properly (possibly through weak starter solenoid) and so not turning the engine, but we may be at odds on perception of the noises involved!

If the starter is constantly and smoothly driving the engine, it's possible you have an intermittent spark or otherwise random problem where the engine fails to start, but we need to set our datum for the noise. If the engine turns in fits and starts in line with the noise, it is a starter problem.

Starters are really easy to change and don't require removal of the gearbox... (sorry)
posted by Brockles at 2:56 PM on January 26, 2008

If I let out the clutch while I'm turning the key and I have it in first, the car will start to move ever so slightly forward, and then stop moving; but it won't kick forward, like it ought to.

This lends credence to the starter potentially being the problem. The starter isn't driving the engine hard enough through being a weak/intermittent motor or through poor engagement.
posted by Brockles at 2:59 PM on January 26, 2008

Happydaz: You seem to know a fair amount about cars. I mean, hey, you just replaced a clutch. Have you double-checked all the basics, though?

That's actually a very helpful perspective. I think I need to go back to basics. I suddenly have some ideas on how to do this-- thanks, all, by the way, for your help.

Brockles: Please god, don't tell me this is the reason you went through all that heartache with your clutch. The failure to start has exactly nothing to do with the clutch. If that really was teh reason, you have wasted an awful lot of time and money...

I know it's almost certainly not the starter. I've changed starters before, and if it was that, well, hell, I would've been really jazzed. I don't hear that telltale click, or a small-motor whirring; I can hear a strong turning of the transaxle. It sounds... well, it sounds just like an engine running, minus the chugging sound that it usually makes. Sort of a ZZZZHHHHH sound, no cranking. No periodic wuh-wuh-wuh that it ought to make if it were cranking.

Let me describe a little the diagnosis I made, and why I changed the clutch-- I've never done it before, as you know, so I may have been a little confused.

We bought this car about six months ago. A little while after, our mechanic, while looking at something else, told us that it seemed like the clutch was going out, and we should watch out for that. This became clear as time went on; during normal driving, even after you'd settle into a gear and let off the clutch, the RPMs would spike a bit before settling down and staying proportionate to the acceleration of the car. Which is to say: it felt precisely like the clutch was slipping.

This gradually got worse and worse, and I started to contemplate the possibility of changing the clutch. One day, while we were driving, the accelerator pedal just didn't work at all any more, and the car died pretty quickly. When we tried to start it, the same thing happened as happens now: that whirring sound, but no engagement. I thought, "this must be the clutch."

But from what jon1370 says:

When a clutch goes bad the engine still runs fine, but the car doesn't move.

... I might have been completely wrong about that. I mean, yeah, it seems like the clutch really did go out, or was on its way; it certainly didn't clutch right at all during normal driving. But if jon1370 is right, then, when the clutch went out, the engine should've kept going; I just shouldn't have been able to move the car.

Brockles: This lends credence to the starter potentially being the problem. The starter isn't driving the engine hard enough through being a weak/intermittent motor or through poor engagement.

That'd be really nice-- I wouldn't mind having changed the clutch too much, it had to be changed at some point, and I'd rather it be something easy, at this point. Furthermore, I thought maybe I'd put the starter back on without a good engagement when I put back the gearbox. But that seems unlikely because (a) this was a problem before, and the car died because of it, and (b) the car simply will not push-start. I just got back from rope-towing it behind my mother-in-law's truck just to try to get it push-started, but to no avail; the whirring continues exactly the same, and the chugging still happens and jerks the car slightly, but not much.

I think this points to an electrical problem-- like a spark-plug thing, perhaps. I'm going to pull those, test them, see what I can do. I've accidentally left my jumper cables back at home, which is half an hour from here, but my mother-in-law is bringing them back, so when they get here, I'll try jumping it, too.

One thing, though: I know the whirring of a starter motor very well, and I'm almost certain that's not it. Even just now, in the car with the windows up and the wind blowing very hard and noisily, I could hear this whirring distinctly and loudly over those sounds. It's not high-pitched; it sounds like the lower-pitched whirring that accompanies the chugging sound of the engine.
posted by koeselitz at 3:30 PM on January 26, 2008

during normal driving, even after you'd settle into a gear and let off the clutch, the RPMs would spike a bit before settling down and staying proportionate to the acceleration of the car. Which is to say: it felt precisely like the clutch was slipping.

Ah, good. Then I think you have just been fooled by two things happening at once. The clutch was slipping for a while, and then the car broke down. No worries. The only mistake was hoping that the car stopped because of the clutch - it didn't. Unfortunately this sent you off on a tangent...

Ok, so this is a standard, car won't start deal. Jumping won't fix it if you have flattened the battery trying, and it won't start with a tow start. It will allow you to recharge the battery to check things, though. Basic is definitely the way to go. Read your Haynes manual for checking the spark plugs (earth them against the engine, and crank and watch for spark, basically). then if you have spark, check fuel pressure (again, the Haynes will be helpful). If you have spark and fuel, you need to check sensors - crank sensor and the like - to make sure the engine control system knows the car is turning over and wants to start.

Start with the big, obvious ones and then move onto the rest. Spark, fuel, etc. My bet is either a coil failure, spark module or similar if it is spark, and pump or fuel filter if it is fuel. When you check fuel (and I am assuming the car is injected) make sure the fuel pump cut off hasn't been triggered (Haynes again).
posted by Brockles at 3:47 PM on January 26, 2008

koeselitz, it isn't clear to me what you are saying about trying to push-start the car: are you saying that there was only a bit of chugging (i.e. engine turning over), not the same chugging you would normally expect when trying to push-start? In other words, are you saying that the engine wasn't always turning over when you had the car moving significantly and in gear? It might help to clear that up.

If the go pedal stopped and the engine died while you were driving, you are right, that probably points to an electrical problem. That was not the clutch. Before you replaced the clutch, what happened when you tried to start it? Have you checked that all the fuses are good? Have you had a look at the relays?

You might want to take you question to the VWVortex (though I hate to recommend it) because these sorts of electrical problems tend to happen to more than one car.
posted by ssg at 4:06 PM on January 26, 2008

I am not a mechanic but I have owned a lot of Volkswagens.... was the car made in Mexico? If so there are a number of known problems with early-mid 90s Jettas from that factory (I have one). I bet some digging around on the internet could give you a list to work from. One thing you might want to look at is the tming belt- there is a seal on, I think, the differential that commonly spews oil all over it and the results of it going are much as you describe. I had it replaced last year

The other thing to do is call a dealer, give them the VIN and ask them which warranty repairs are outstanding. Mine had a laundry list when I got it.
posted by fshgrl at 4:29 PM on January 26, 2008

1: You don't need to touch the clutch pedal to start the car. Put it in neutral and it is essentially teh same thing from your perspective.

Just for the record, this isn't true for all cars ... some Toyotas, for example, require the clutch to be depressed to turn over.
posted by Rumple at 4:30 PM on January 26, 2008

Right after I posted that, I wondered if there was some sort of microswitch (like that which is required to remove the auto trans from park) that may disable the starter motor unless the car is unquestionably in neutral (ie the clutch is depressed). I certainly have never seen one on a VW but the underlying point (that the clutch itself cannot stop the car from starting) is correct still. The switch like that at the pedal of a Toyota (apparently) may stop it trying to start, but that's it. I'm sad that it is considered necessary. Electronics to help the stupid have neevr been on my list of 'good things to have'. They deserve to bump into walls when they start their cars, I say...
posted by Brockles at 5:02 PM on January 26, 2008 [1 favorite]

To continue this little derail, Brockles, my 2000 Jetta has just such a switch and they seem to be pretty common on recent vehicles (Toyota trucks even have a button that you can press to disable this function). That said, my father has a 1996 Jetta and I'm quite sure that I've started it without pushing in the clutch.
posted by ssg at 5:34 PM on January 26, 2008

To be brief: Start by verifying that you have fuel (at the business end of the injectors) and spark at the plugs; I'll assume you have air. If you have those two, go on to look for more complicated things.
posted by mosk at 5:56 PM on January 26, 2008

if it turns over but doesn't sound right, especially if it died while driving, perhaps the timing belt broke.

depending if it's 16 valve or not, it may just need a new belt, or it may need a new motor.

does it have a distributor cap? if so, pop it off and have someone crank it. if it doesn't turn, or starts and stops, you may have a problem.
posted by KenManiac at 6:29 PM on January 26, 2008

But it doesn't turn over, and I've checked the timing belt. It makes sense: I'm not hearing any significant turning over, so there's no ignition. Either there's no electricity, or there's no fuel.

And the slight turning-over sound that I do hear fades slowly in and then fades slowly out, which makes it sound like it's not electrical-- if it were, then it'd jump in and jump out faster. I'm pretty sure it's on the fuel line. The fuel pump was replaced a month and a half ago, so I doubt it's that (I sure hope not). I'll try the filter and check the line tomorrow.
posted by koeselitz at 9:50 PM on January 26, 2008

I might be totally off here (not familiar with that make / model at all), but I wonder if the starter isn't engaging properly? Normally makes a helluva racket, but maybe not so much if it's well worn. Usually due to the starter solenoid going weak & not engaging the starter pinion properly - it might partially engage, but then slips off under load.

(I've also seen the odd reduction starter with an internal clutch pack and continuously-overdriven pinion, as well as old overdrive starters, but I'd bet it's neither of them...)

koeselitz: you're a little unclear - when you say "turn over", is the engine itself (as evidenced by watching the valve train / front pulley (harmonic balancer), etc) rotating at a reasonable rate i.e. a few tens of RPM at least, not dead slow? Or do you mean that it's turning OK, but not starting to catch & fire?
posted by Pinback at 12:08 AM on January 27, 2008

But it doesn't turn over, and I've checked the timing belt. It makes sense: I'm not hearing any significant turning over, so there's no ignition. Either there's no electricity, or there's no fuel.

Unless this is terminology, that logic doesn't make sense. If, as I said earlier, the engine spins at a constant rate on the starter (maybe take the plugs out and try it to isolate anything else) then the starter is not turning the engine over - all this means is that the engine is forced by the starter to turn at (as Pinback says) at tens of RPM. If it isn't turning like this, it has nothing at all to do with fuel. Either you are confusing us with your terminology, or you are getting distracted by things.

If by 'turning over' you mean 'trying to start' and referring to 'chi-chi.BRRR-chi-chi-chi-BRR' type noise, then we are getting somewhere. However, nothing you have said so far suggests fuel without hitting the basics. Back to first principles before doing ANYTHING else:

Does the engine turn over on the starter motor at a reasonable rate?
Do the spark plugs spark when out of the engine and earthed to the block and teh engine turned?
Is there fuel pressure at the rail - loosen the feed fitting to the injector rail a little and see if it spurts. If it doesn't, tighten it up, crank the engine again and loosen it. No spurting, no fuel pressure). If you have pressure, try cycling the ignition with it loose and see if it continues to spurt fuel while the pump runs (the pump will run for a few seconds every time you flick the ignition on.)

Unless you are leaving things out, you seem to be jumping to solutions and not discounting the obvious first in a logical order. Do that first.
posted by Brockles at 7:34 AM on January 27, 2008

Don't know if anybody's still around to read this, but I'll hope so. Here's an update. (Gah, this is getting frustrating.)

I took Brockles' and Pinback's advice and started over on diagnosis, going over the simple stuff first. First of all, the starter motor: I took it off, checked and cleaned off the gear on it, made sure it fitted nicely against the flywheel, and then remounted it. Second of all, there's fuel pressure at the injector rail, at least, so I know that fuel is going to the engine. Third, there's a spark on the wire going into the distributor cap, so I know it's at least not the coil, and I replaced the cap and rotor just as a matter of course.

It still sounds exactly the same. Let's see if I can describe that a little better. At the moment I first turn the key, I hear the whirring of the starter turning the flywheel; it's a deeper, ZZHHH sound, which makes me think that the flywheel is turning well, although I guess I'm not certain. It sounds very much like the engine is running, except for one thing: there's no chugging, no guh-guh-guh. As I keep the key turned, the engine starts a very distant chugging, and it starts slowly and builds up, and then fades back: ZZHHH - ZZHH - ZH - WUH - WUH - WUH - ZH - ZZHH - ZZZZZHHHHH.

I was thinking just a moment ago that it must be the spark plug wires. I did my old-fashioned rough test-- pull the boot off the plug, hold the end of the spark plug wire to another piece of metal to ground it, have someone else turn the key, and see if there's a spark-- but I saw nothing. I don't know if that's conclusive, and I unfortunately don't have an ohmmeter, although I can get one fairly easily. Now I realize it might well be the injectors, but there's no leaking and no smell of gasoline except when I pull the line running into the rail off. It spurts when the key is turned, in fact it pops off if I put it on partway and turn the key, so the fuel pump is working and there's pressure.

I checked the timing belt again: it's fine. In fact, we had it replaced a few months ago too, so it shouldn't have trouble, although I should say that fshgirl helps me a lot in informing me that this is a Mexican car: we've always had that problem with oil dripping on the belt.

I'm stumped. I worry about the clutch itself or the tranny because if jon1270 is right about this:

...if you hear any chuh-chuh-chuh at all then your engine IS turning over. It may not be firing or starting, but all turning over means is that the engine is being spun by the starter motor.

...then my engine isn't turning over, and, beyond just firing and starting, the crankshaft isn't being turned. Which is bad, I think.

Thoughts?
posted by koeselitz at 5:40 PM on January 27, 2008

Third, there's a spark on the wire going into the distributor cap, so I know it's at least not the coil, and I replaced the cap and rotor just as a matter of course.

You need to know it is getting to the spark plugs, though. Take a plug out, stick it back in the plug lead and hold the whole thing (with insulated pliers) against the engine metal bits (with the end of the spark plug in contact with the metal. If you get a nice, strong blue spark (probably at 0.3 to 0.5 Hz occurrences) then the spark is fine. Just trying to earth the wire isn't reliable, as the spark will be too dissipated to be conclusive.

Now I realize it might well be the injectors,

It's unlikely to be the injectors unless it is electrical - ie the injectors are not being fired. They're pretty simple things and all four failing at once is so unlikely as to be close to impossible.

...then my engine isn't turning over, and, beyond just firing and starting, the crankshaft isn't being turned.

I'm still totally confused by your use of 'turning over'. Watch the crank and get someone to hold the starter on for ten seconds. The crank should and all the pulleys on that side of the engine should turn at a fairly constant speed until the key is released. This is turning the engine over. Literally just rotating on the starter alone. Whether it fires or not and runs has to be after this point.

From your description, I am wondering if it is coughing into life and immediately dying again. One possible source of this is not fuel pressure, but fuel flow. If the filter is clogged, or the pump weak, it can put enough pressure at the fuel rail to get it to start, then it will immediately die as it is not man enough to maintain pressure while some is being used. Take the return line off the fuel rail (after the pressure regulator), point it into a bucket or something and crank the engine for a few seconds. Do you get any fuel? If you do, then all seems well with the fuel system.

So, if you get a a nice fat blue spark, and lots of fuel, either the injectors aren't opening, or the engine doesn't know when to fire them (so a timing issue - sensor broken or something).

Although, I still can't get my head around this confusion about the engine 'turning over'. After you have looked to see if the engine is physically rotating in time with the starter, disconnect the coil lead and see if it does the same thing. It may be that the engine momentarily catches and tries to run, kicks the starter out (which it does at a certain rpm) and then not being able to keep going.

Is there any way you can video it trying to start and post it on vimeo or something? Maybe after you have tried teh above?
posted by Brockles at 5:59 PM on January 27, 2008

Also, forget about the clutch and transmission. It has nothing to do with that. If you didn't remove the flywheel and the engine is actually doing something other than a 'click' when you press the starter, you didn't screw anything.

You seem to be jumping around a bit and leaping to possible solutions. You really need to stop worrying about what it might be, and slowly knock over the things it can or can't be. I think the potential expense of the problem is distracting you.

Deep breath, and we can hit the issues one by one. Fuck it, set up a webcam, and we'll do this all together. That'd be cool as hell...
posted by Brockles at 6:03 PM on January 27, 2008

Brockles: Deep breath, and we can hit the issues one by one. Fuck it, set up a webcam, and we'll do this all together. That'd be cool as hell...

Awesome. Awesome. The best I can do, I'm afraid, is a video from my mother-in-law's camera, but I can do that, I guess. If there's something that it'd be useful to film, I'll do that. I'll take a vid of the car trying to start.

More in a moment. Be right back.
posted by koeselitz at 6:24 PM on January 27, 2008

Right on, this is fun and hopefully helpful!
posted by snsranch at 6:31 PM on January 27, 2008

Even the sound of it "turning over" (which I suspect it isn't) would be cool.
posted by Rumple at 7:02 PM on January 27, 2008

Yea, it definitely sounds like the starter gear (solenoid problem) isn't engaging the flywheel. Good luck man!
posted by snsranch at 7:11 PM on January 27, 2008

Okay, a few videos are here. At least in those you can hear the revving and how it sounds. In the first, you'll see that the engine is turning, as Brockle was saying above that it ought to; I was speaking wrong, sorry, it's just that there doesn't seem to be any explosion in it. You can hear for yourself.

There's a longer video that I made that I'm trying to upload of me testing the plug wires. I'll have that in a moment; I've found a way to do it. Just a sec...
posted by koeselitz at 7:56 PM on January 27, 2008

Ok. The car is turning over fine. What is kind of hard to hear is whether the car is nearly firing and so turning faster than the starter (toward the end of the video) or whether it is falling off the starter. My feeling from the noise is it is pretty damn close to starting.

For terminology purposes, there is no revving (the car needs to be under its own power for that) and the car appears, for some reason, to be turning over at a speed slightly different to the starter for small periods.

My immediate suspicion now is spark or poor fuel delivery. I am awaiting the next video.

Isn't this exciting?

Can you tell (from the manual of that car - ie Haynes) what is in the ignition system? Just a coil, distributor and leads? No 'ignition pack' on the side of the coil? We need to see what is at the plug, really.
posted by Brockles at 8:04 PM on January 27, 2008

Okay. Let's try this.

Video 1. This is my assistant (well, my mother-in-law) turning the key while I film. You can see that the engine is turning, though it's not starting, and you can hear it.

Video 2. This is an overall view of the engine during an attempt to start.

Video 3. This is me testing the plug wires by having her turn the key while I hold them to the metal on the manifold. First one of the wires from the distributor to the plug... then the wire from the coil to the distributor... then another one of the wires from the distributor to the plug. As you can see, there's plenty of spark coming from the coil to the distributor; there's a significant amount less coming from the distributor to the plugs. I don't know if I'm losing a lot there, or if the much tinier spark I see is natural. I guess you guys can probably tell me.
posted by koeselitz at 8:09 PM on January 27, 2008

Brockles, that last vid should serve your purposes-- let me know if it doesn't.
posted by koeselitz at 8:10 PM on January 27, 2008

And: this is awesome.
posted by koeselitz at 8:11 PM on January 27, 2008

The problem with the coil end of the wire (as I said earlier) is that the dissipation is so high, you may not see the spark properly. The coil spark looks good, but as I said before, the plug wire to the engine test is useless unless you have a plug in the end.

Take a plug out of the engine. Stick it in the end of the plug wire, and hold the plug against the engine (bottom end touching the engine while you crank it). It is hard to tell if there is no spark at the plug end from just the wire, as the lack of concentration of the spark may be misleading. We need to see what the plug itself is doing...
posted by Brockles at 8:24 PM on January 27, 2008

The main problem (he realises after he posts) with the 'wire to the engine' method, is that the connection is so far from the block due to the shielding. So the natural loss of spark is hard to quantify.


Also, if you get a strong blue spark at the plug (much like the coil one) then you have a fuel issue. Go back to what I said earlier as to not only needing pressure, but also needing flow. Once we have established flow and pressure at the fuel rail, we can work out whether the injectors are opening or not. We're (potentially) looking ok for spark at this stage, although we need to prove spark at the plug. Faulty wires (again, all four failing is unlikely) usually mean poor running, not not running. Once we have spark at the engine, we have discounted that element, but the fuel/timing issue is still relevant - in the delivery of enough fuel and the control system of opening the injectors.
posted by Brockles at 8:28 PM on January 27, 2008

it looks like the spark stops when the engine sounds funny.

the plug wire terminal is quite a way up inside the metal shield, it has a good chance of grounding to it rather than the block. unless the rotor is missing or really funked the spark looks OK.

not sure why it goes away, but..

spray some carb cleaner or starting fluid into a hose on the intake manifold. (there's some 13mm (1/2 inch) or so hoses on there. puli one off and give a half-second shot into the manifold, then try starting it.

fuel pump relay went bad?
posted by KenManiac at 8:30 PM on January 27, 2008

Well the starter does sound funky, but it's turning the engine over. There is plenty of spark. Next up, fuel.

This is super old-fashioned, but, you can determine if you have a fuel problem by removing a spark plug and putting (not pouring) just a wee bit of gas into the cylinder and then try to fire it up again.

If it acts like it wants to run but can't quite do it, then you need to check your fuel system.
posted by snsranch at 8:32 PM on January 27, 2008

is there a central ground for the injectors that maybe didn't get put back on when the tranny was out?
posted by KenManiac at 8:32 PM on January 27, 2008

On preview, what KenManiac said.
posted by snsranch at 8:34 PM on January 27, 2008

Righto. I'm off to take video of that.

Brockles: For terminology purposes, there is no revving (the car needs to be under its own power for that) and the car appears, for some reason, to be turning over at a speed slightly different to the starter for small periods. My immediate suspicion now is spark or poor fuel delivery.

Ah. I'd thought that might make a bit of sense. One small piece of info that might help: it appears that someone (I'd guess the guy that sold it to us) put new plug wires on three of the plugs, but the fourth wire and the main line from the coil are older stock wires. They look heavier-duty, black, with, of course, the VW/Audi insignias on them, but they also look older and feel stiffer. I'll try to get good images of them. My question at this point: is it at all possible, given what you say about the turning speed being off, that one bad plug wire would do this? My impression, maybe wrong, was always that a car should start if one plug wire was going bad, it would just misfire often; and it somehow seems unlikely that all of them would go bad at once, although... this is a car that's been sitting for two months while I've been working on it, so it's possible that that's complicating it enough to make one wire keep it from starting. Or is this a timing issue?

People say I tend to overthink things. I think that's what I'm doing now.
posted by koeselitz at 8:35 PM on January 27, 2008

AND FOR GODS SAKE, MAN, ISOLATE YOURSELF FROM THE SPARK PLUG LEADS!

Use a (dry) rag to hold the Coil/Spark plug leads with. Those things have massive voltage in them. If something goes odd, you may have a serious issue.

A story for you - I was (with friends) running a racing car (a modified road car, with an engine of the same style as yours, but a Ford) and it failed to start for qualifying. We were doing much as you were, but in a hell of a rush, yet one of my friends was holding the end of the lead when someone misheard, said "Now?" and cranked the engine.

Cue friend going a bit white and needing to sit down rather rapidly. I hesitate to use the phrase "keeled over" but let's say it would be mostly appropriate.

While we (the important bit to us) got the car out for qualifying and into the race, our friend spent the next two hours hooked up to the track's own heart monitors trying to work out if his irregular heartbeat would sort itself out, or whether he'd need hospitalisation... He was, as it turned out, fine, but the episode exposed a weak heart condition that he didn't know he had (he was 26 at the time) and it could have been a whole lot worse.

Moral? Don't fuck with spark plug leads. Hold them with plastic handled pliers or a dry cloth. Oddly, I've been a bit careful with them ever since.
posted by Brockles at 8:36 PM on January 27, 2008

Also, I'll try those things, snsranch and KenManiac. And I'll look for any lack of ground, or anything I forgot to reattach-- although I'd looked around before, maybe there's something I detached without knowing it.
posted by koeselitz at 8:38 PM on January 27, 2008

My question at this point: is it at all possible, given what you say about the turning speed being off, that one bad plug wire would do this? My impression, maybe wrong, was always that a car should start if one plug wire was going bad, it would just misfire often; and it somehow seems unlikely that all of them would go bad at once, although

Your inner feeling is right. Cars with shitty leads misfire. They don't fail to run. Engines with poor spark getting to two or more pistons will at least TRY to run. This is not about the wires, but more fundamental.

Also, spark plug leads cannot affect how fast the engine turns on the starter. That purely depends on battery power and good electrical connections.
posted by Brockles at 8:40 PM on January 27, 2008

(I find it extremely unlikely that there is a ground relating to the engine on the gearbox. It is more likely to be on the left of the engine, as you look in, and be bolted directly to the block.)
posted by Brockles at 8:40 PM on January 27, 2008

Okay. Back.

First of all, I checked the spark plug leads. Safely, like you said, Brockles; I just set them and the camera up and went to turn the key, so I wasn't anywhere near them. (Also, I made sure to test this before testing the gas line.) Spark plugs one, two, three, and four seem to be getting juice, as you can see. Also, fuel is going in and coming out of the injector rail.

So I can't figure what it could be. I guess it could be the injectors. I know that I really wish that the Volkswagen people hadn't put that manifold right on top of the spark plugs and the injectors.
posted by koeselitz at 10:31 PM on January 27, 2008

At this point, I imagine that everyone has pretty much gone to bed. I'm about to, anyhow, as I've got to get up at five tomorrow morning in order to catch the bus back down to Denver to go to work. (Blah.) Thanks for helping; I'll keep you posted on what happens next. I'll most likely be back tomorrow night to go over some of this.
posted by koeselitz at 10:34 PM on January 27, 2008

This is fun. Thanks for all the help, everybody. I'm going a little nuts at this point.
posted by koeselitz at 11:12 PM on January 27, 2008

Yeah, spark all seems good.

What immediately struck me about the fuel demonstration, is how easily fuel flowed out of the rail and so after quickly after cranking. I'll have a think about it (on my way to work in a minute) but it has occurred to me that the pressure at the rail may be an issue.

The injectors need pressure (usually about 3 or 4 bar) in the rail to open the injectors, and then an electrical pulse to allow the pressure to actually activate the injectors and squirt. If you don't have one or the other, you don't get any fuel injected.he video, but if they weren't, then either the pressure regulator is buggered (ie just letting fuel past and so not building enough pressure to fire the injectors) or the electrical pulse for the injectors is not firing.

I'll need to try and remember how to check for that, electrically, mind you. The easiest physical way is to pull the injector complete (or reassemble it after removal) and stick it in a jar/tray and crank it and see if they squirt, but you say you need to remove the inlet manifold to get to them? There must be an easier way than that...
posted by Brockles at 5:13 AM on January 28, 2008

easiest way to check injector pulse is with a 'noid light. it's an LED that plugs into the injector harness and flashes when it gets the 'injector open' signal.

failing that, an LED test light will work. not so sure about an incandescent one.

pull the vacuum line off the fuel pressure regulator and suck on the end. put your tongue over the hole. does it hold vacuum? if not, reg is no good (if so, it may still be bad).

get gas in your mouth? it's bad.
posted by KenManiac at 6:59 AM on January 28, 2008

Brockles: ...you say you need to remove the inlet manifold to get to them?

Yeah. I found a picture of somebody's engine compartment-- it's not mine, but it's a 2.0 Jetta from around the same time, and it looks about the same (although less dirty and dingy). You can see the end of the rail sticking out over the distributor cap. It's actually a lot easier to get around underneath the manifold than you'd think-- the spark plugs are there-- so if I don't need to pull it directly up I might be able to get it out. Otherwise, I wonder how hard it is to pull off the manifold. Probably hard. Eh well.
posted by koeselitz at 7:22 AM on January 28, 2008

It looks to me like you can get the rail off without disturbing the inlet manifold - it won't be a difficult job to remove anyway, but will involve a reasonable length of time and some gaskets. Leave it on unless absolutely necessary.

Ok. Things we need to nail down:

1: Is the fuel getting into the cylinders.

2: Is the spark timed correctly to the fuel delivery.

Causes for 1being a 'no' - ie if the plugs are removed after cranking for a while (20-30 seconds max) and they are dry at the ends (being as we have established fuel at the rail):

1.1 - Insufficient fuel pressure at rail (through failure of pressure relief valve).
1.2 - Insufficient fuel pressure at rail during cranking (through fuel pump being able to produce pressure but not maintain it) - this is unlikely, as there was pressure after the pressure relief valve on the rail return.
1.3 - no electrical pulse to trigger injectors (possible causes are crank position sensor being broken and/or other electronic control issue).

To test these:

1.1 - Now, I'd never recommend this, as this is seriously bodgy, but if it was my car (I think my back is nicely covered now), I'd 'fake' back pressure in the line by clamping/blocking the return line in some way (do you have one of those brake line clamps, or a pair of vice grips with something to avoid damaging the rubber hose?) and I'd crank the engine and see if it coughed, tried to run or did anything different after that. If the plugs got wet (even if it didn't fire) after this, but not before, you have a pressure regulator problem. Don't do this for too long though, as over pressure is not a great plan. If the engine fires, turn it off immediately and go and buy a pressure regulator.

1.2 - This is unlikely/not a problem. The car would initially cough and fire but die almost instantly. I suspect there is no issue with the fuel pump.

1.3 - The pulse test method as previously suggested would work, or (if it was my car, etc, etc ) I'd take the rail off, take the injectors out and connect everything back up with the injectors exposed and crank it and watch. Be sure to clean all the o-rings on the injectors after you do this and try not to drop the ends of them in any crap.

If one is 'yes' (the plugs are wet):

1.4 - spark is mistimed (crank sensor, or other electronic control issue). It is unlikely to be the crank sensor now, as I think it'd not fire at all if it was faulty. It's a Hall effect sensor, it isn't all that clever...
1.5 - Possibly cold start valve faulty? This is unlikely, as I still think the car would try and start more than it is. But it's worth considering.

2: This could again be crank position sensor or control module issue. Again, I am not sure this is likely. It's possible a control box died, but if it did, I don't think it would spark at all. I think the only reason the spark may be mistimed is if the sensor goes, but again, I think it would at least TRY and start. It'd run like crap, but it'd try.


I think fuel isn't getting to the cylinders. My guess is pressure regulator or injectors not firing, at this stage. Should give you something to try, with all the suggestions from various people above.
posted by Brockles at 4:47 PM on January 28, 2008

Hey Brockles, I'm curious about 1.2 - Insufficient fuel pressure at rail during cranking (through fuel pump being able to produce pressure but not maintain it) - this is unlikely, as there was pressure after the pressure relief valve on the rail return.

How was that pressure determined? I'm curious because although I totally agree with you notes above, it seems to me that he's probably not getting any fuel at all.
posted by snsranch at 6:00 PM on January 28, 2008

Well, there must be enough pressure (Assuming the PRV is working) to flow fuel through the return - therefore the pump is ok as it has enough power to pop the PRV and still flow.

If the PRV is not ok, then there is no pressure in the rail but still plenty of flow - ergo the fuel pump is not stopping the car from starting. Maybe not yet, but it certainly isn't the issue for now.

Admittedly it is an assumption, but one that points toward the PRV needing to be borked before there is any chance of the pump being screwed.
posted by Brockles at 6:11 PM on January 28, 2008

Yep, that makes sense. But now I'm stumped and will have to wait for the results!
posted by snsranch at 7:45 PM on January 28, 2008

There will be results? :)
posted by snsranch at 3:46 PM on January 30, 2008

Hey snsranch, Brockles. Sorry about the wait here; I'm trying to get a chance to go back up to Boulder so I can work on the car and use the veritable manual that Brockles wrote for me up above. Unfortunately, that's hard for me to do, given I work and ride the bus an hour every morning and an hour every night to and from work, I'm having trouble making that happen. I will be up there Friday night, though, and should be able to be doing this 7pm - 9pm MST, 9pm - 11pm EST.
posted by koeselitz at 9:10 AM on January 31, 2008

/books webcam slot
posted by Brockles at 9:39 AM on January 31, 2008 [1 favorite]

By the way, I am here, and on the job, and will be back to report in about half an hour here.
posted by koeselitz at 6:14 PM on February 1, 2008

Woo Hoo! Good luck man!
posted by snsranch at 6:29 PM on February 1, 2008

I'm here, too. Although, for reference, "I'm on the job" means a totally different thing to the context you use to an Englishman, and Mrs Koeselitz would be most upset if you were diagnosing your car in the middle of that...
posted by Brockles at 6:51 PM on February 1, 2008

Okay: back. Unfortunately, it begins to look like I can't do too much more tonight.

First of all, the plugs are dry when I run the engine for about 30 seconds and then pull them. (Strange thing happened: this time, when I first turned the key, the engine backfired, and then went back to doing what it's been doing.) So it seems like no gas is getting to them; they're dry as a bone.

Second, I tried Brockles' "bodgy" 1.1 test suggestion, and clamped off the fuel return line running out of the rail. Nothing significantly different happened; it tended to try a little bit harder to run, but only slightly.

Third, the manual tells me I've got to remove the intake manifold to get to the fuel rail. I'm not too apprehensive about this, but unfortunately the one thing I haven't got at this point is a set of Torx wrenches, and the manifold is all held on by Torx bolts. In fact, even just the rail is, so I can't even experiment with pulling it off alone.

However, here are some pictures of the situation, just in case anything can be gleaned from them about how I'm going to get the rail off. [ 1 2 3 4 5 ] It looks very much like I will have to take off the manifold. Thoughts?

On preview: well then, I'm very much not on the job, I guess. You crazy monarchists talk funny.
posted by koeselitz at 7:09 PM on February 1, 2008

Ok, so we have established that the injectors aren't firing. So it's either the pressure reg, or something electrical in the control system. I'm not entirely sure how to test for that on those cars. Does your manual suggest a voltage that needs to be present at the plugs for the injectors or anything? Although I think it'd be too quick acting to see. A pulse gauge of some sort? I know you can use an oscilloscope, but I'm not sure you'd have one of them hanging around...

Well, if you do take the manifold off, you need to make sure you clean it properly without scratching the surface, and replace the sealing gaskets. A leaky inlet manifold will make it run like a sack of crap, although you may be lucky and get it to seal enough with Blue Hylomar (instant gasket) enough to try it without buying all sorts of parts straight away. Mind you, removing the inlet manifold is involved and perhaps lengthy, but not really difficult. I think we need to discount electrical or pressure reg issues, as there is only now any point in taking out the injectors to change/check them individually.

I'd be tempted to look at getting a pressure regulator tested if you have anyone local that would do that. Just as a crazy idea, though, do you know anyone with a similar age golf or jetta that would let you borrow the pressure reg for 5 minutes? They're 90 bucks to buy, so it may be worth being sure, and you could do this without even taking the rail off - just pull out that u-shaped clip and pull it up (against an o-ring pressure only). Swap the other one in, crank it and see if it starts or the plugs get wet. At least we'd see if there was a difference.

I thought of another way of testing the reg (I think) - I think the cold start valve (basically a fifth injector) is fed at fuel rail pressure, and this should spray when the ignition comes on, and/or when you crank and is not connected to the rest of the fuel rail so should be easier to remove. If you can get to that (there is a rough diagram of it here although the rest of the diagnosis is not relevant). You could take that out and crank and see if it sprays fuel. If it does, then we know we have fuel pressure. If it doesn't, we are no nearer until we work out out if the problem is electrical or not, as it still could be either. Does that make any sense?

As it is quite a job taking the manifold off and may not be necessary, then getting the regulator tested, or trying to get/borrow a pulse tester for the injector loom/testing the cold start injector is where I'd be tempted to start working on next. Maybe do some online research or ask a local garage if they have a portable means of testing the loom that they'd be willing to let you borrow against a deposit as your next source of investigation.
posted by Brockles at 8:29 PM on February 1, 2008

I'll check into that tomorrow. I'll let you all know.
posted by koeselitz at 9:31 PM on February 1, 2008

I'm back.

In case anyone was wondering: when the Haynes manual says you have to take the intake manifold off to remove the injector rail, it's full of shit. You just have to have dexterity in your fingertips, that's all.

The fuel rail is out now, and I'm going to reconnect everything with it exposed in order to see what happens on the injectors when I turn the engine. I'll post some documentation when I do... probably in about forty-five minutes.
posted by koeselitz at 5:43 PM on February 2, 2008

The Haynes manual is full of shit? Who saw that one coming...?
posted by Brockles at 5:46 PM on February 2, 2008

You'll probably find the Bentley manual a much better value in the long run.
posted by ssg at 5:59 PM on February 2, 2008

Yeah-- that Bentley manual is looking to be a little gift for myself when I finish all this shit. Every weekend, I think to myself, "well, I'll be done this weekend; no use ordering a manual now." Every weekend for two months. Ah well.

Test is all set up. Camera's even set up. Running out to film it now-- back in a few.
posted by koeselitz at 6:06 PM on February 2, 2008

Back. Check this [ 1 2 ] out. Looks like plugs are injecting fuel, and doing it in a timed way.
posted by koeselitz at 6:25 PM on February 2, 2008

So I begin to conclude that the spark is mistimed. Am I correct?
posted by koeselitz at 7:01 PM on February 2, 2008

Hmmm. Due to the fact that I was drunk last night, I slept on this one. It is a weird one, that's for sure.

We have spark. We have fuel. We don't even try and start. No coughing, no spluttering. Nothing.

Well, we SAY we have fuel, but you tried earlier and got no fuel on the spark plugs, right? Which would mean that it wasn't getting into the cylinder, although it did seem to be coming out of the injectors.

As an outside chance:

Being as the spark and injectors are clearly seeing some sort of timing, and it being unlikely that it was sufficiently mistimed not to try and run if there was a load of fuel being pushed into the cylinder that saw a spark later, I am still unconvinced (despite the logical path) that fuel is getting into the cylinders.

Have you tried to start the car again during any of this (since trying the blocking of the PRV?) I'm just wondering if you'd disturbed something without realising, and had reconnected it during all this. Because that much fuel getting into the cylinders would certainly make the plugs wet after 30 seconds of cranking. We know the injectors work, so refitting them and looking for any damaged wires that we may have inadvertently fixed during the process (maybe they are bent into a break when installed and when relaxed like this, reconnect). Worth checking.

This is a weird one. Because even if the car ran like crap, it SHOULD fire with the situation as it is at present.

When you try and start it, do you touch the throttle at all? Or do you leave it well alone?

I'd also test the cold start valve (fifth injector) just to be on the safe side, but the total lack of fuel on the plugs says to me we still have some weird issue, or we've fixed it and not realised!
posted by Brockles at 10:25 AM on February 3, 2008

Spark mistiming: On reflection, I don' think the car would entirely fail to start if it was mistimed. I think it would just run badly. I've put plug leads on entirely wrongly before and the car has started, just ran like crap. Not starting at all is weird. It suggests fundamental issues - like one of the three essentials missing.
posted by Brockles at 10:26 AM on February 3, 2008

Yeah, I was thinking that. If the timing was off, there would be at least some fuel getting to the spark, and something would happen.

Brockles: Have you tried to start the car again during any of this (since trying the blocking of the PRV?)

Yes. In fact, this morning I reinstalled the injectors, since it occurred to me that I might've plugged the right thing in inadvertently, and tried cranking it: same problem.


When you try and start it, do you touch the throttle at all? Or do you leave it well alone?

I don't touch the throttle at first, then I begin to, although I've tried starting it pumping the throttle all through and not at all, as well. When I pulled the injectors and did the test, I noticed that they fire fuel whether I'm pumping the throttle or not, so I haven't been pumping the throttle lately so much.

It suggests fundamental issues - like one of the three essentials missing.

You mean: fuel + air + spark? Yeah. Could it be air? I checked the air filter, and it doesn't look very old, still bright yellow.

The only other detail I can think of is the fact that I just now remember that the tranny oil leaked out a lot when it was taken off, and I've been meaning to top it off again, but haven't. But I can't think of any way that could possibly lead to this problem.

My wife made me promise that if I couldn't get it running today I'd take it to a real mechanic. Begins to look as though there's really no other recourse.
posted by koeselitz at 11:10 AM on February 3, 2008

I'm also starting to wonder whether I should get a flashlight and look in those injector holes-- is there any way something could be blocking them? It doesn't seem like it, somehow.
posted by koeselitz at 11:17 AM on February 3, 2008

Unless there is a blockage in the inlet manifold or the air filter box (serious blockage like a birds nest/dead rodent/collapsed pipe etc), I can't see how it could be air. Weird. I'd take the lid off the airbox and look up the tube and see, but it'd be the first time I have heard of it.

The injectors will fire fuel regardless, but you will change the amount that they pump (you won't be able to see the difference). Either way, if you've cranked over for a while, I'd expect fuel on the plugs.

No chance of the engine being affected by the gearbox oil. You'd be able to start the engine without it even having the gearbox on the car if you had something to bolt the starter to.

I'm stumped. This simply doesn't make sense. Even if the Air flow meter (bolted to the inlet manifold) was screwed, I can't see how it wouldn't at least run a little bit. I'd pull the plug off of it it and try again to discount any issues there (if it can't get a reading it may try a default map to start it) but without getting my hands dirty and/or testing individual components I have no idea. Even if we hit the problem now, it'd still not leave me any sense of achievement, as we're trying EVERYTHING and it's only a matter of time!

This is pissing me off, now. I can't help feeling we're missing something obvious, but I'm buggered if I know what.
posted by Brockles at 11:28 AM on February 3, 2008

I'm also starting to wonder whether I should get a flashlight and look in those injector holes-- is there any way something could be blocking them? It doesn't seem like it, somehow.

I'd find it extremely unlikely that all four holes got blocked simultaneously, but at this stage I'm considering animal sacrifices, so by all means look.
posted by Brockles at 11:29 AM on February 3, 2008

It's a great cause of annoyance to me, too.

I'm going to go check if the plugs are getting we again.

Hey: thanks for sticking through on this.
posted by koeselitz at 11:35 AM on February 3, 2008

You know, at this point, I begin to suspect the spark again. Looking at those vids, it sometimes took a long time for a spark to come off of the plug. It may be that it was sapping out of the plug wire and grounding out.

Odd thing I just noticed: one of the plugs had no gap at all. I have no idea how that could've happened during normal functioning of the engine. Maybe it was my error.
posted by koeselitz at 12:28 PM on February 3, 2008

But, after gapping all the plugs, it still doesn't start. And I think I've bollocksed up one of the plug wires trying to remove it with some pliers (yes, I'm an idiot.) I've covered the hole in the insulation with a huge glob of electrical tape, but it's not shorting out briefly after I turn the key every time. This is annoying, as all turning stops and the car alarm goes off. I fear I may be destroying this thing.
posted by koeselitz at 12:30 PM on February 3, 2008

I watched them all again this morning, you know, for the same reason. But I put most of the issues down to the way they weren't earthing very well. They moved when you cranked the engine, and so the spark was dissipated on a couple of them. Checking the gap is obviously a good thing, but unless they were all screwed (And two certainly showed extremely strong sparks) I'd expect the engine to have coughed and farted and maybe just not kept running.

If you get a nice blue spark when holding the plug with the threaded end against metal (all previous provisos aside) then it should be good to at least fire a couple of times. Even with weak sparks, often cars will start.

Were they wet?
posted by Brockles at 12:33 PM on February 3, 2008

Sounds like low battery. Stick a charger on it before you go any further. If it has issues, it definitely won't start with low juice.

I think I've bollocksed up one of the plug wires trying to remove it with some pliers (yes, I'm an idiot.)

They're a bugger to get out on those cars. I'd have used pliers, too. The fact you damaged them so easily (I hope you had the pliers on the metal and they slipped off?) may point to them needing replacing, but I've never known plug stop a car starting - just make it run lumpily. The car I referred to that had been sat for 5 years after an engine bay fire (in the gearbox thread didn't get new leads before we got that running.
posted by Brockles at 12:37 PM on February 3, 2008

They weren't wet; at least not on the contacts. The threads were slightly moist. They smelled of gasoline, but then, so does the entire garage, so maybe I'm imagining things.

I should see an actual sheen of fuel if they're wet, shouldn't I? I can't chalk this up to the inherent dissipation of fuel in air.

You're right; we got strong sparks from most of those.
posted by koeselitz at 12:37 PM on February 3, 2008

I actually slipped far enough to tear up above, where the plug wire is thinner. But I only tore the insulation, revealing the second layer of white fiber insulation underneath it; and I've covered it up.

Yeah, it'd occurred to me that the battery was low. I'll go jump it again and see what happens.
posted by koeselitz at 12:40 PM on February 3, 2008

All charged up. No more clicking out and dying with the car alarm running, but same problems.
posted by koeselitz at 12:51 PM on February 3, 2008

There wouldn't be fuel actually on the contacts if they spark - even a weak one, as it will evaporate/burn of that even if it doesn't fire. The slight wetness sounds pretty right to me - after all the pistons are blowing air past it anyway, so some of the fuel will be evaporated/blown off. It won't be like pouring fuel on them. Wet enough that it shows on your fingers and has changed the colour of the plug threads is as close enough to normal as can be expected.

Dammit, but this is a weird one. I've got to say I'm stumped. Maybe the time has come to give in...
posted by Brockles at 12:58 PM on February 3, 2008

Yes. A new, fresh set of eyes will make sense, I think, and I hear good things about the mechanic down the road.

This has been pretty great, anyhow, and I've learned a hell of a lot. You will be updated.
posted by koeselitz at 12:59 PM on February 3, 2008

I'm convinced that this is a timing issue. I know on older cars timing is adjusted by turning the distributor and often it could be turned so far as to not fire at all. Sadly, I don't thing your distributor works like that. I think your model is stationary. (If it is adjustable, though, give it a try!)

Oh, well. Good luck with the mech and it's probably going to be a very simple fix.
posted by snsranch at 3:22 PM on February 3, 2008

It's possible, yes, but unless the pulley jumped a tooth (and I see no reason for it to do so) this happened while driving. Which is odd for timing. It's certainly worth pursuing. I've had cars quite a way out on timing that have still ran, though, and nothing as been taken apart that can have been put back wrong.

Certainly possible, though. It has to be something unusual I feel at this stage, as all the obvious stuff has been discounted.
posted by Brockles at 3:30 PM on February 3, 2008

Brockles, yea, this is pretty odd. It should at least try to fire at this point. I'm very interested in what the mech has to say about it.
posted by snsranch at 7:14 PM on February 3, 2008

have you checked the compression? i still think it's possible there is a cam timing issue.

maybe pull the valve cover or timing cover of and see what it looks like i there.

we have spark, we have fuel. if timing is off far enough, it won't run at all. if valve timing is off far enough, you get no compression. won't run.

puzzled.
posted by KenManiac at 9:23 PM on February 3, 2008

snsranch: I'm convinced that this is a timing issue. I know on older cars timing is adjusted by turning the distributor and often it could be turned so far as to not fire at all. Sadly, I don't thing your distributor works like that. I think your model is stationary. (If it is adjustable, though, give it a try!)

Timing is adjusted on the 1996 Jetta via the Electronic Control Unit (ECU). The ever-helpful Haynes manual (grr, can't wait to get that Bentley at this point) advises me not to try this myself, and says that I have to take it to a certified professional now. I'd try anyway, but I have a feeling an electronic adjustment is somewhat beyond the ken of my ratchet and driver set, unfortunately.

Haven't checked compression, as I don't have the tools for that, either. But that's the other thing that had occurred to me as a possibility, too.

I'm going to call the mechanic today. It should be interesting. ("Look, here's a long list of the things I've tried on this bugger...") However, there are two or three things like this (others: pressure regulator, exact charge from spark plugs) that I don't have the equipment to test, but which should be elementary for someone who does. Once he can say exactly how much juice is going in and exactly what fuel pressure's going in and exactly what the compression is and exactly what the timing is, it's certain that he'll be able to tell where the weak link is. I'm optimistic, as all of those besides compression is a relatively easy fix.

Also, I need a new plug wire anyhow at this point, so it'll be good to have that replaced.

So: place your bets, gents. I'm taking it over to an ingeniously-named garage called German Auto tonight or tomorrow. I think this warrants a Metatalk update, so I'll post in there when I get the verdict.
posted by koeselitz at 8:19 AM on February 4, 2008