Mechanics

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

1999 GMC Sierra • 150,000 miles

I have 1999 gmc sierra 4x4 5.3v8 regular cab
Avatar
Terpfan
October 25, 2011.



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.

Rasmataz
Oct 26, 2011.