It never ends... 16v monotronic in need of loving.

[spasticone]

Ok. I have yet another problem with my darling passat. After the posts I've made about it, everyone probably thinks I should take my cars to a mechanic, but hey, why start now..lol.

92 passat 2.0 motronic

I just did a head gasket and am having problems getting it to run. It starts on the cold start valve, but dies when it needs the regular injection to kick in. I know it has to be a wiring problem or something, but I just don't know. I've been over it 53 times, and can't seem to locate any probs. When you first start it, (like when it sat overnight), it runs for maybe 15 seconds. After that, it dies. I don't think it's timing, though it may be off a little, because it starts and sounds good. It runs off of a bottle of gas being shot into the intake so I'm almost sure its a fuel delivery prob. I have preasure at the line at the distribution block. I don't know exactly which solenoids, switches, etc keep the injection from working, but any input would help as I am ready to push this car off a cliff. If you need any more info on the problem, by all meens, PLEASE ask. Thanks again.

[boschmann]

Without a CIS injection gauge you are severely limited. Check the injector seals & plastic inserts for leaks. You can spray starting fluid around them & see if it tries to run off it. Check for other vacuum leaks like holes in the intake air boots. Try lifting the air flow plate manually to see if it runs that way. It is best to do it through the mixture adjust hole with a long allen wrench, but you can do it by hand if necessary.

[spasticone]

I don't have any vacuum leaks that I can find. Starting fluid will keep it running half heartedly when sprayed in the air box intake side.
Just a few "check questions. Timing on a 16v is just by the cam mark and tdc right? If I use the flywheel tdc and the valvecover mark I should be right on, but with this thing it is ALWAYS 1/2 tooth off. the only marks I see on the flywheel are a line and a 0 an inch and a half (or so) from that. I'm going with the line since on the othe 47 vw tb's I have done it was ALWAYS right. The intermediate shaft is not alighned in a 16 valve? because the cams run the dist.

The other Question.. on the back of my block I have a one wire sensor that I believe has never been hooked up. What is that? Looks like an oil preasure switch. nothing on my wiring diagrams about it, but I figured I better ask.

This car was running PERFECTLY before the headgasket so this has to be a problem I created.

Grrr. I hate this car. I have a cabrio waiting for me right now so the wife can have a nice little beater. Through my many vw's I have never disliked a motor like I hate this motronic 16valve. I would trade it for a 98hp 8 valve in the blink of an eye. Ok.. sorry for the venting. Thanks for your input.

[boschmann]

The timing mark on the cam is set with the flywheel 0 mark, not the line. Intermediate doesn't matter on the 16V. Did you replace the injector seals when you had them out?

[spasticone]

OK.. The timing is now set correctly for sure. It seems I have a broken wire or sticking solenoid or something. when I set and checked the timing for the 23rd time I hooked up the intake tube and it started and ran great. I took the tube back off and rechecked the T Belt and pushed the 2 little solenoids that run in parallel under the intake tube onto the air box plate (the hold on with the little rubber grommets) and tried it again. it started and shut right off. Grrrr... so I pulled the boot on the air metering part and lifted the air flow plate by hand. it runs great by lifting it to the correct level. What could the prob be??? is that a vacuum leak??? Oh yeah... I didn't pull the injectors so I didn't put in new seals, but I don't think I have a leak there. I tried starting fluid around them with no change. I dunno.. it's wierd because it was just running good. I hate intermitant Thanks for the input.

[boschmann]

Have you adjusted the idle mixture by turning the 3mm hex on the air flow plate arm?

[spasticone]

No.

[boschmann]

Then I'd go back to a vacuum leak problem. The two little solenoids are for the ECM to ajust the idle for A/C on & if the idle gets too low. The intake air boots can have cracks hidden in the folds of the accordian sections. I think you should have an idle stabilizer valve (1 1/2" diameter by 6" silver cylinder near the valve cover) which you may want to clean out with throttle body cleaner.

[spasticone]

OK... It pissed me off too much that this car ran when I started, so here I am... Yet. ... When I start it after it sits the night, it idles for about 15 seconds. then it's like something warms up and kills it. I know it's a vacuum prob, but I don't know where. when I hooked the wiring back up i did switch the cold start and ISV for one start attempt. Could that have hurt anything? What else could dump air in and kill my vacuum. I am almost completely sure I don't have an "external" leak. is there anywhere else??? I fixed the head leak and copper coated the intake this time so I'm ok there. I'm just at a loss. Oh yeah... the one valve... I believe the on/off solenoid gets hot after I leave the key on for a while...


Thanks for any input.

[boschmann]

Unfortunately you really need to check the fuel pressure. I've seen a few CIS test gauges on eBay.

[spasticone]

FIXED!!! Holy crap was that simple. I knew it was gonna tick me off so bad when I figured it out. I'm so happy I could shoot something.

The computer needed reset. I disconected the battery and reconnected and Voila'.... Perfect Idle. I can't even believe it... Well... Thanks for all the help. I found the info on the Russian VW pages. Man.. Those russians...