This is not an Audi but it is CIS so I'm hoping someone has had this problem......
It's my 300ce with the m103 engine, usually when it's warm and have my foot off the
throttle(rolling up to a stoplight) it will stall....it fires right back up but it has done this
several times now and its becoming more than just a small inconvenience.
It is KE Jetronic right? Do you have a CEL? I bet there is a way to blink out fault codes similar to KE Jetronic VAG cars. I once had a problem with my CGT (also KE Jetronic but a 5 speed)where it would sometimes die coming to a stop or going around corners or over bumps. The hall sensor plug on the distributor was loose. Another time it had a similar problem and it turned out to be a corroded connnection in the fusebox at the fuse for the Jetronic ecu. It probably also has an Idle stablilizer valve and an idle switch. I would probably make sure the isv system is functioning properly.
First I checked the OVP relay and found the fuse was gone, changed the fuse and the car started easier and idle improved but every now and then would still stall. Put a new fuel filter in and a bosch cap and rotor, checked the wires and plugs and still, on occasion it would stall. It is happening more often of late and the only difference is the temperature.
It's really been no big deal when I'm driving....I just pop it into neutral and it starts right up but the wife drives this car daily and her response is to STOP put in park and restart :roll: it's a little scary.
I was thinking maybe the idle stabilizer valve but I don't know much about the CIS.
Before it stalls though the idle drops a bit....4-500 rpm normally it doesn't drop below 600.
Oh,I forgot about vacuum leaks, you should check for those first. KE Jetronic has an adjustment for idle CO%, IIRC, which does affect the quality and stability of the idle. Instead of a frequency valve, the KE jetronic has a differential pressure regulator (DPR). To Adjust idle CO% you basically monitor the current going to the DPR and turn the CO adjustment screw through the hole next ot the fuel dist until a certian DPR current is attained. You probably want to find a manual with this procedure and fix any vacuum leaks first.
Will it stall when the radiator fan comes on or the AC compressor kickes in?