Quote:
Originally Posted by agfours
.....- there is a warmup cycle / loop that I believe is triggered by several things including the O2, the CHT sensor, and one more I can't recall.
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I think it might be the Air temp sensor in the AFM. Ref and Speed sensors figure into the equation as well as the AFM door position wiper.
Quote:
Originally Posted by yelcab1
With some other cars, when the engine is cold, the ECU runs open loop and slightly rich waiting for the O2 sensor to warm up, then it uses the O2 sensor signals to tweak the stoicheometric mixture. But, I do not know about the 87 Carrera firm ware.
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I got a book on the Motronic engine management system to satisfy my curiosity once, and while I am not expert, I think you hit the nail on the head. While waiting for the O2, the ICV gets adjusted and idle is a bit high, but when things warm up, the ECU adjusts the ICV and the idle drops to normal. I've forgotten a lot of what I read, so hopefully folks will forgive me. Steve's code is much more efficient.