91 4.0l automatic np242 with code 24,

91 4.0l automatic np242 with code 24, the throttle position sensor. This is a brand new sensor. Yes I did reset the computer. If I drive it for a while the code resets. Anyone have any suggestions? It has been lacking power and only getting 9 miles to the gallon. It does have a small crack in the exaust manifold would this be causing my problem.
thanks, John McHorney

livewire said:

It does have a small crack in the exaust manifold would this be causing my problem.
thanks, John McHorney

Click to expand...

Yes, the crack is likely causing a problem, but I doubt it's the sole cause of that terrible gas mileage. I don't recall if the TPS is adjustable on the '91, but I want to say it isn't. Please verify.

Did this poor performance come about AFTER you changed the TPS? If so, perhaps you got a bad TPS or incorrectly installed it (not seated)......?

When was the last time you changed out the O2 sensor? I assume your throttle body is clean, IAS is clean, good plugs, cap, rotor, etc?

Code 24 on a '91 is the TPS's output voltage being over or under normal values.
From Mitchell Manuals Online:
1. Turn ignition on. Check TPS output voltage at center terminal. With throttle closed, voltage should be .20-1.5 volts.
2. Slowly open throttle. Voltage should gradually increase to 4.1-4.8 volts at wide open throttle. If not, make sure 5-volt input and ground circuits between TPS and engine controller are okay. If TPS output voltages are not as described, replace TPS. TPS is not adjustable.

HTH

Thanks guys. I will check the voltages and post back the results.