I've been posting a little here and there trying to find out my problem.
95z a4 94k miles. On a cold start it will die after about 5 minutes. I started it during the day and on the first start I had the a/c full blast and in neutral and died in about 5 minutes. Started it back up, no a/c, 10 minutes, ran fine. When I started it up the second time i was just messing with the steering wheel and noticed something. When I turn the wheel back and forth, the rpms drop from 550-650 down below 500 and the car wants to die, but it won't. When driving one cold morning I was at a stop light and took off real smooth and drove over a dip in the road and the car will stall or die (3 times in 2 weeks so far). It's the same dip in the road and happens in the same exact spot.

Haven't had time to change out cap/rotor/plugs/wires (have all msd and NGK stuff). Don't have any scan tools or special tools. Plan on changing out IAC valve and get a stock coil and a new fuel filter while I'm at it.

any other suggestions or do you know what might be wrong?
thanks

 

coil and ignition control module sounds like the problem to me

 

very well could be.

could be a short in any of the fuel system...when you hit the dip it spikes the power to ground...shutting off the car. i had a problem with my jeep recently...i know it's not the same car or manufacturer but it's still electronic....any way...my fuel pump power wire was shorting to my gas tank skid...and i was blowing fuses, but sometimes they wouldnt blow, it would just shut off the pump.

or, it could be a short in the coil.


either way, it's time to replace the coil, cap/rotor, and the wires. this may fix the problem. you might want to go ahead and buy a whole opti-crap...i'd get accell if i was doing it...and keep it safe.

 

I would check over the connections/wiring on the battery and parts of the ignition system for corrosion and good connections.

 

I second that thought. I had a slight power steering reservoir leak that coated the chassis ground cable and was causing sputtering and occasional no start conditions. I cleaned it up and shielded it off and no more problems.