HI I have a 93 accord f22a1. I just finished rebuilding the engine and trans and the car for the most part runs pretty well except the engine rpm does not drop while coasting with either the clutch disengaged or the trans in neutral. Depending on gear and speed the coasting rpm will remain near, or increase from, the rpm while under load. Also the rpm will remain high until the car has completely stopped for about 3 secs then idle returns to normal (around 800 rpm). I have checked the Idle Air Control, Fast Idle, and Air Booster valves for leaks, but all check out. My next thought is that it could be the TPS or ECU, but i have not investigated either one. I would just like some input on what could be causing the issue or a solution. Thanks.

 

you rebuild the engine and transmission? did you replace the pilot bearing/bushing with the correct one? was there any trouble fitting the transmission back up with the engine? also, what all did you replace during the trans. rebuild?

 

The transmission was technically not a rebuild as there weren't any parts replaced. The trans was inspected all synchro's hubs and gears were fine. The only thing that was altered was the final drive, it was replaced with one from a 98 prelude. Everything went together smoothly including the remount to the engine.

I diagnosed further and found that either the IAC or possibly the ECU could be the problem. After unplugging the IAC and going for a drive the problem is gone just now have a pesky CEL and shitty idle with the high beams on for now. Going to try a junkyard replacement IAC for now can't spend $200+ on a new one.