1990 Chevy Truck fuel system

1990 CHEVROLET TRUCK
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SCHUMAN_07
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  • 5 POSTS
Engine Performance problem
1990 Chevy Truck V8 Four Wheel Drive Automatic N/A miles

I have a 1990 1/2 ton 4x4 5.7L....my problem is that when my truck idles the motor runs perfect but when I push the throttle down past 1/4 way it bogs down and starts to mis-fire and sometimes back fires. I have a brand new fuel filter and a semi brand new fuel pump......any advice?
Jun 16, 2010 at 10:00 PM
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RASMATAZ
  • CAR REPAIR CONTRIBUTOR
  • 75,992 POSTS
Inspect and test all the following listed below:

Oxygen sensor.
Catalytic converter.
Fuel injectors dirty/sticking.
Mass airflow sensor/Airflow meter.
Throttle position sensor.
Manifold absolute pressure sensor.
EGR Valve
Fuel pressure regulator leaking or defective fuel pump.
False air leakage.
Fuel contamination.
Foul/defective spark plugs.
Open spark plug wires.
Ignition coil/Coil packs defective.
Incorrect ignition timing.
Cap and rotor.

Note:If it doesn't apply disregard
Jun 17, 2010 at 1:06 AM
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