Hello everyone. I have a 1990 Hf, I have a hesitation from idle to about 2500 rpm under a load (and only under a load). This is what I have done and checked out: Major tune up including NGK plugs, honda wires, cap, rotor, pcv, fuel filter, air filter, injector cleaner, timed the engine. I unplugged the tps and the car run smoothly, smogged it the other day and it failed on both HC and CO. I was told it could be the tps, but I am wondering if it could also be the ecu or tps wiring to ecu. Also, why would the car run smoothly with the tps unplugged. Thanks for any help you can provide.

 

Yea I think it might be the ecu

 

tps is a major input. if you unplug it, the cel will be lit and your pcm goes into back up mode.

car runs but will not be perfect coz your pcm is basically relying on your map sensor (partner incrime of tps) .

you could actually test the tps with the voltmeter with the key in the "on" position only, backprobe the signal wire and move the throttle slowly back and fort you are looking for a sudden drop in the voltage from .5 to 4.8 volts