I am working on a swapped 87 Blazer it has an 0411 PCM in it and everything is running great except cold starts.
When I cold start the car the IAC desired and actual read 0 and you have to use your foot to keep the car alive. Once the car hits about 55C or 130F IAC desired jumps to 310 and the engine idles up to 1500 rpm and then slowly decreases down to desired idle. Once it is fully warm IAC is around 40-60 at 212F.
I have the default IAC position set to 210 and had it to 310 a while back to try and see if maybe the logger just wasn't reading the desired IAC. The weird thing is is that it still defaults to 310. Any time you start it above 130F the car will immediately jump the desired IAC up like normal and step it down but I tried flashing it back to 210 and it still goes to 310.
I have done a few days of cold starts and no matter what below 130F desired IAC is 0.
Have any of you experienced this?
I am guessing it is the pcm but not sure. There are 0 codes and 0 air leaks. I have checked headers, intake and tb for leaks.