1996 GMC C3500 Tune up

1996 GMC C3500
10,900 MILES • V8 • 4WD • AUTOMATIC
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ONAWAVE
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My GMC truck runs a little rough when cold, but better when it's warmed up. It will seem to jump a little after it warms up at highway speeds. I replaced the gas filter, spark plugs and wires, but it still does it. It's a 454 engine. What else needs to be replaced for a tune up? What would make it "jerk" while driving? Thanks
Jan 12, 2008 at 6:35 AM
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MASTERTECHTIM
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did you change the cap and rotor? if not id do that first. jerking on highway usually is a misfire from a ignition component. the other thing to check is the egr valve. if it does not vent fast enough you will feel a skip at steady throttle like on the highway. to check it just unplug the egr valve and see if the problem goes away. good luck
Jan 12, 2008 at 7:00 AM