Gary Kitchens

New up and down stream o2 sensors, new air temp sensor, new coolant temp sensor, new tps.

Still huge plume of fuel dumping out on hard acceleration.

Bosch sensors,

Fuel pressure 48 psi steady while running.

No misfire, runs very smooth, idles goodles with a teeny burble now and then.

Ideas??

Bucaslaker

I'd think to check fuel injectors, ignition system (spark plugs, wires, cap/rotar,) and maybe even your catalytic converter. After they're on for a while they kind of clog up. Usually it comes with a loss of power as well as bad mileage. But with all the extra strain to get up and go you can expect bad mileage on acceleration if that's the case. Also, and I don't mean to insult, but when I hit the gas hard on my 91' the gas guage drops almost an eighth of a tank until I'm cruising, it's just a temporary scare and that may be your psychosomatic problem.
Those are my ideas.
I'm young but my hands are old.
Hope this helps.

Bustedback

Are you getting a rotten egg smell from the exhaust?

Gary Kitchens

OK, I drove her again, lights came back on, pulled and cleaned both o2 sensors and the new Manifold Air Temp sensor, and all went back to normal 8).

I think the entire time it was the Manifold Air Temp Sensor, it was filthy when I replaced it, I think residual blow by or EGR blow by got on the new sensor, a little MAP sensor cleaner took care of it and all is good to go now.

Sorry for the delayed report, I lost all my login info then got busy at work.

Next problem is new/old at the same time... new thread coming after a search.

Bustedback

There is no EGR valve on a 4.0 after 1990.

Gary Kitchens

I said egr, but I simply meant the ccv tube going from vc to the intake manifold at number four intake port in the manifold