carmelo

I have searched the archives but have not come across my unique problem. I have a 90 C4 that I drive mostly on the weekends. Sometimes not at all for say 2 weekends straight but I make a habit to start it and drive on the weekends to maintain battery power (although I have a battery maintainer). On my weekend drives I take the same route and drive about 30 miles and return home searching for leaks, problems, etc on the car.

My problem is after I start it up all is fine. I leave home and about 2-3 min or so off driving and crusing to a stop, the car looses power and shuts off. I calmly start it up and it runs fine for 30 miles on my route back home. The amazing thing is that it always shuts off after 2-3 minutes at around the same area or stop sign! It is pretty consistant. Any one have a similar problem or can explain.

I live in Northern California, so the temperature is not too cold or too warm to cause and issue. Any ideas?

Thanks,
Carmelo

brookewebb

Your car has become 'aware' and is taking the stop sign rather too literally. I suggest a stern talking to.

Failing this check the cylinder head temp sensor.

darth

This was a sympton I had but after resoldering the 15pin connector on the clock it hasn't done it since.

Hope this helps
Bill
90C2

nirich

Sounds like something is warming up to a certain temp and shorting out??
No xmas tree lights?
Does it start first time when cold? How about when hot? Mine didnt like starting hot every now and then.....changed the DME relay, old one had slight burn marks on the contacts and seemed pretty damn warm.
Maybe coils tracking once they get hot or maybe the DME relay?

Not a lot of direction in my thoughts there.....but gotta start somewhere!

carmelo

Nick,

Yes, I should have mentioned that I do get the "Xmas tree lights" effect when it shuts off. But after that no problem and runs well. Only happens at a cold start. Hot starts are no problem. I have not pulled the DME relay or reset it because besides this problem, it has been idling well and driving well. Maybe I should pull it and take a look. I hope the DME is not that smart and learned to perform this shutdown every 2-3 minutes after a cold start.

Thanks,
Carmelo
90 C4

carmelo

Bill,

Thanks for the reply, but I have not done any soldering.

Carmelo
90 C4

carmelo

Brookewebb,

As funny as that sounds, I am starting to think the DME "learned" to shut off at this stop sign!

Thanks,
Carmelo
90 C4

Rennen

I wonder if it is your O2 sensor that is bad or shorting out? I seem to recall that the system doesn't engage the O2 sensor for a couple of minutes because the engine needs to warm up a bit first.

dfinnegan

The o2 sensor is ignored at startup, but it only takes about 90 secs to bring it on-line.

bmohr

I have a similar issue. I think it might be dirty knock sensors, probably clock needs resoldering as well but here is my issue at the moment. Car starts fine, drives fine. However after 3-5 minutes and when engine warms up the cel comes on and immediately the car starts running like ****. Low power, rough idle, you know the deal Wires are newish, caps and rotors look fine, belt is intact, new DME relay. Can the O2 sensor pop a CEL? Edited to ad, if I turn off car, and restart the cel goes away again and it pulls strong as ever.

cjoenck

Tiptronic or Manual? Yes, 02 sensor drives input for CEL through DME - the computer, not the relay. Also check recall item was done on MAF connector. It might take a few minutes to heat that area from the engine. Finally, check connections around throttle body, WOT, etc.

Good luck.

bmohr

It was the O2 sensor. Upon removal I saw it had a pretty decent ding in it. Must have gotten slammed by a large rock or bolt on a drive and knocked it off line. Runs smooth and strong and no cel. Thanks cjoenck