engine is hesitating unless I accelerate hard

1999 GMC SIERRA
150,000 MILES
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TERPFAN
  • MEMBER
  • 1 POST
I have 1999 gmc sierra 4x4 5.3v8 regular cab When i am driving at 40-50miles an hour and have to slow down to say 30 and then speed back up it hesitates and jumps unless i mash the gas then it moves i've replaced spark plugs,air filter,fuel filter and transmisssion filter
Oct 25, 2011 at 5:31 PM
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RASMATAZ
  • CAR REPAIR CONTRIBUTOR
  • 75,992 POSTS
Could be caused by one of the following below

Oxygen sensor.

Catalytic converter.

Fuel injectors dirty/sticking.

Mass airflow sensor/Airflow meter.

Throttle position sensor.

Crankshaft position sensor

Knock sensor

Manifold absolute pressure sensor.

EGR Valve

Fuel pressure regulator leaking or defective fuel pump.

Fuel contamination.

Foul/defective spark plugs.

Open spark plug wires.

Ignition coil/Coil packs defective.

Incorrect ignition timing.

Cap and rotor.
Oct 26, 2011 at 1:01 AM
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