I've got a 93 accord that we just completed an engine swap on and after cleaning the FITV and the IACV and it is still hunting bad. I have tried 2 different throttle bodies, IACVs and FITVs, 2 different ecu's and it is still hunting bad. The TPS is good and both valves are good. There are no apparent vacuum leaks all the bolts are tight on the intake manifold, all vacuum lines are connected all the gaskets appear to be fine but the car never stops hunting even at operating temp and the coolant system is fully bled of air. Any more known problems that could be causing this? Any help would be awesome.

 

I would double and triple check all vacuum lines. i had a similar issue with my 95 and it turned out to be a vacuum leak in the intake system.

 

I agree, double check.

When I seafoamed my car through the brake booster vacuum line she was hunting like crazy!