2.0 starting problems - CAS or ignition module?

[anth]

hey guys, been having some dramas with my 2.0 lately, past few months or so.

- Car is sometimes hard to start, vary rarely, usually after short drives. This can usually be overcome by having the ignition cranked and the accelerator pedal all the way to the floor, then it comes to life. Like I said though it's very rare.

- On 3 occasions in the past 6 weeks, the car has died on me while idling, shortly after starting up and taking off. On 2 of those occasions, the car started back up normally, but on one occasion it took a while, had to use the technique mentioned previously.

- Have taken it to my mechanics to check but they couldn't find anything wrong with it, it never played up while it was in their care (doesn't that always happen!) Going off my explanations they think it is either the crank angle sensor or the ignition module/coil

- This morning I took off from home and did two short drives (approx 5mins each), on returning to the car after the second drive it wouldn't start, even after trying to crank it at W.O.T. Had to resort to calling the RACV guy. We pissfarted around for about half an hour, he took one lead off the ignition module/coil and tested it, found there was no spark. Decided at that point to tow it to my mechanics. We gave it one last crank and it magically started up, so I drove it straight to my mechanics and it's there now.

So we still think it's either the C.A.S. or the coil, I'm thinking of just replacing both to (hopefully) put this issue to bed. The ignition module is right at the front of the motor, I'm thinking I'll just replace that myself, if it doesn't work then I'll get my mechanics to do the C.A.S. since there's a bit of labour involved I'd rather leave that till last.

Has anyone had the same experiences that I'm having?

[grtuned]

normally the crank angle sensor will log a fault in memory, ive seen this issue before where no faults are logged but still having issues stalling while driving and then re-starting, Your at the point where you may need to try different options to try resolve issue, i'd suggest starting with the fuel pump relay and the Terminal 30 relay then test and see how it go's. This is the cheapest way to check without throwing alot of money at it. But if your 100% that no spark was there when checked you may need coil pack first.

[anth]

Well the RACV guy took a lead off the coil pack, then attached his own testing lead and there was no spark. So my mechanics think it's either the coil pack itself, or the C.A.S. is playing up and stopping the coil from working.

One thing I'm spewing about is my mechanics said if the RACV guy tested the injector module while the car was failing to start, then we'd know for sure which one is the culprit.

[Ironman]

Just a word in here.... I was driving my car and it would intermittently cut out like it was starving of fuel, then give it 5 mins and it would be fine to drive for a while. I quickly got the ****s with this problem. It ended up being the C.A.S. I know that the Mk4's are diff to my MK3 but the new Mechanic that fixed my beast said quite often you get a false negative with the VAGCOM and won't show up the C.A.S error. Usually the coating on the wire starts to crack and split, the heat in the engine gets to the sensor and shuts it down. In mine however the plastic connector that joins the 2x 2-3mm probes to the cable had cracked/oxidized/crapped out. The probes are Copper covered Iron so when the heat gets into it the copper expands and renders the probe faulty. Don't quote me 100% as i'm still a NOOB. But thats my recolection of the conversation, I was just estatic to have my car back and driveable lol. Also probably didn't help that this happened 150 k's from home on the way to a family funeral.
Anywho the C.A.S in the Mk3's you need to usually jack the engine up out of the front engine mount and remove the oil fliter to get to housing. I say run with it you might spend more money replacing a not so necessary part but saves you doing it later.. Common prob in MK3 & 4's.

Good Luck

[anth]

Just to bump this up for future reference for anyone having similar problems, I took my car to get scanned on the weekend and it came up with the engine speed sensor/crank angle sensor being the culprit. Can't wait to get it fixed and have my car back to normal!

[funkymonkey]

Hey Anth, I'm looking out for a decent mechanic to do a full service on the 2.slow. Just came across this thread and it reminded me that you've got the same as mine. Any recommendations?

[anth]

I've just been using my usual mechanics that I've always gone to with my other cars (Protek), I've never gone to a VW specific workshop, but I'm sure there's plenty of links around here of places like that if that's what you're after. I got the scan done at a VW dealer though.

[anth]

Just to keep everyone updated, I bought a crank angle sensor from VW and my mechanics installed it in less than half an hour, just in case anyone else gets an exuberant quote for the same job.

There is some good info in this link...
VWVortex.com - TECH: MK4 2.0 Crank Position Sensor P0322

Now the true test begins, gotta wait and see if the car stalls on me or fails to start one day. It already feels better to me though, it's starting much stronger and feels smoother.