1999 GMC Other Repair Question
Asked on June 5, 2008
Models missfire on #4 cylinder
Engine Performance problem
1999 Other GMC Models V8 Four Wheel Drive Automatic 98000 miles
this is a 5.7 vortex engine i have replaced o2 sensors all 4,fuel injectors the upgraded ones ,fuel pressure regulator, fuel filter,rotor cap and rotor , sparkplugs and wires, ignition coil and moduler,performed pressure checks in all cylinders 3x each and cylinders on 1,2,3,5,7 pressure is 180 and on 6 is 170 and on 4 pressure was 160,165,160 and replaced throttlebody gasket, intake gasket valve cover gaskets and after i tried higher graded fuel but i am still getting the same codes misfire on #4 cylinder. i replaced everything that the dealer had diagnose. what else could it be do someone out there have a clue or experiencing the same pain.
1999 Other GMC Models V8 Four Wheel Drive Automatic 98000 miles
this is a 5.7 vortex engine i have replaced o2 sensors all 4,fuel injectors the upgraded ones ,fuel pressure regulator, fuel filter,rotor cap and rotor , sparkplugs and wires, ignition coil and moduler,performed pressure checks in all cylinders 3x each and cylinders on 1,2,3,5,7 pressure is 180 and on 6 is 170 and on 4 pressure was 160,165,160 and replaced throttlebody gasket, intake gasket valve cover gaskets and after i tried higher graded fuel but i am still getting the same codes misfire on #4 cylinder. i replaced everything that the dealer had diagnose. what else could it be do someone out there have a clue or experiencing the same pain.
Asked by Suburban99