Hey guys whats up. I just bought an 88 accord for the winter. When I bought it is was running fine. After unplugging the ECM to do some work to the car it has aquired a bad idle while in park or nutural and while in drive it seems as though the idle is too high.

This is the scenario. When I start the car it runs fine until the motor heats up and goes into closed loop. As soon as it goes into closed loop the revs jump between 1000-1500 steady while in park or neuteral. And while in gear it seems as though the motor has too much momentum the revs are around 1100 with my foot on the brake!

I was thinking it might be the IAC motor or some sort of vacum leak, but it wasn't doing this before. Any ideas, would be much appreciated...

 

Might try re-setting the idle, the idle air screw will back itself out sometimes, throwing it out of spec.

Check the cooling system for any lose of fluid, causing air to get trapped in the system...