Posted by Charlie Petit on November 12, 1998 at 16:57:09:
In Reply to: Crappy Idle, only when its cold. '80 528i posted by Michael Lytle on November 12, 1998 at 16:41:41:
: I've recently been diagnosing a longstanding pebble in my shoe. It's not life threatening, but it bugs the crap out of me.
: My 1980 528i idles very low when its cold, maybe this is normal, but my understanding is that it should idle faster when its cold, then slow down when it warms up. My car idles great when its all warmed up.
: I believe that my aux air valve works.
: My thermo time sw, and temp sensor seem to work.
: My o2 sensor is probably junk, but that shouldn't be it.
: I replaced the injector seals, helps alot in other areas but not here.
: Any info about it would be great, this seems to be the reverse problem of most people and therefore I have found little help so far on the web.
The aux air valve is the only thing that is going to increase the idle when the engine is cold. If it is not working then you either have a bad valve, or the temp sending unit (not the thermo time switch) could be bad, or the wiring between these devices and the engine controller could be bad. It is also possible the the engine controller itself is bad, but if this is your only simptom, it is highly unlikely.
I hope this of some use to you.