First post. I have 1990 gt and I completely rebuilt the motor. It runs poorly on startup like multiple misfires. Once it warms up it runs smooth as hell. I have tried a lot of parts testing and diagnosing. What I see happening is something in opem look causes this to run like crap. I've searched forums for days and can't find what exact sensors are being used in open loop. All I know is if I cold start is and It running terrible, all I do is unplug ect sensor and engine runs perfect. Plug ect back in and engine runs like crap...can't figure out what that means, bad maf? When I unplug ect does that send it to closed loop instantly? If so it runs amazing. I just don't know enough about all the sensors and computer based on cold or warm engine. Any ideas.?