brianrich07

I am having a severe lean condition. It's so bad the motor will run hot going down the free way. I have a decent scanner and the short term trim seems to be fine but the long trim stays at 32. I have literally replace everything on the fuel system in the past month. Fuel pump regulator both oxygen sensors IAT sensor map sensor and clean the tb. Does anyone have the specs on the fuel trim. Thanks in advance guys.

Turbo X_J

What brand O2 sensors, 1996 is a transition year if the motor wants to bake you maybe SOL. Have you done a compression test?

brianrich07

Denso sensors. And the motor is pretty fresh. Only 45000 on a rebuild. And it has a 3 row radiator in it. I know it's a fuel problem because I will fall on its face after 3/4 throttle.

Turbo X_J

Whats the fuel pressure in psi? TPS/wiring could also be flaky.

brianrich07

Haven't had a chance to check that yet. But the pump isn't but a month old. It is an Airtex so that may be the problem

brianrich07

Tps has been changed. It's in spec.

Turbo X_J

Airtex not so good as far as reliability, you'll fare better with a Bosch.

brianrich07

Yea I think I'm going to warranty it out and get a new one and try that.

CCKen

Check the fuel pressure at the rail with the engine running (at idle and under light acceleration) before yarding out the pump.

The O2S/PCM fuel trim is an odd duck. If you have a bad injector that is running rich, the PCM will lean out all injector pulse widths so the O2S will see a lean condition, and you will see a (+) STFT in an attempt to enrichen the F/A ratio. Just a thought.

When checking your fuel pressure do the leakdown check and see if the fuel pressure bleeds down too fast (below 30 psi in less than 5 minutes). If the pressure drops off rapidly you may have a leaky fuel injector.

If you can't afford a Bosch pump (like me) Carter makes a good pump.