This is my old Corolla, now my Mother's. It currently runs mostly smooth while in park or neutral, revs up smooth. But in gear, it hesitates and will not even hit 2k RPMs.
It WAS running so rough that it could not even run while parked without stalling. It acted like a plug was not even firing.
Tested and replaced all plugs already with NGK Iridiums. Tested and all coils are firing. Cleaned out the MAF and throttle body, including around the butterfly valve. Ran seafoam through it. TPS measures .4 volts at idle and smoothly moves up to just under 7 volts when open, no spikes or drops. Fuel flow is fine, and the fuel pump was replaced by somebody else who was sure that was the problem. MAF was also replaced a few months back.
After the cleaning, the engine was running smoother and could run without dying like it was before. Revs up really smooth, so my efforts improved it. Put it in any gear, and it will only run at idle speeds and idles pretty high. Push on the accelerator and it feels like it is doing NOTHING.
I am suspecting the TPS but know little about the correct voltage range for it or how to adjust it. She cannot afford to take it to the stealership. I feel I am close to the problem since a thorough cleaning improved it. Don't want to spend money on a new TPS without knowing for sure.
Any advice appreciated. My Mother is without a car until this is fixed.
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