m750rider

I have a 1991 S4 that within the last couple weeks is doing something odd.

On cold startup, it begins to run quite low - about 500 rpm, then within a few seconds ramps up to about 1000 rpm which is more like normal. It will also do it occasionally on a warm start and I might have to feather the gas pedal to keep it running. But once it resets itself it idles perfectly at about 700 rpm for the entire rest of the trip

Prior to this on a cold start usually it would go immediately to 1000 rpm or so.

I've pulled the two spade connectors off the Temp II sensor and each shows no continuity to ground.

I've got the WSM but I can't really figure out what controls cold start idle by reading it.

I also show a check engine light once in a while that lights and then goes out after a while. Never on start, but during a drive.

I've tried to read the code without the tester, but in spite of following the directions (gas pedal full throttle, engine off, switch ignition on till lamp flashes, etc) I can't get the system to flash the error code. Odd because I've done it before.

Any ideas? Thanks

m750rider

Sorry, I tested the wrong sensor instead of the Temp II - I checked the intake temp sensor for the fan controllers. I'll let you know what I fin on the Temp II

m750rider

Both pins read 1.38 K ohms at about 100 F