2003 Pontiac Grand Prix Misfires or torque converter

2003 PONTIAC GRAND PRIX
103,000 MILES • 6 CYL • FWD • AUTOMATIC
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SISSY03
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The car misfires on acceleration and bucks (possible engine miss) but when you hit accelerator and kicks down it feels like its in neutral and you can hear a wobble. Snap on scanner reads engine misfire on all cylinders and it also reads possible "TCC" (torque converter clutch) We have changed all spark plugs and wires and replaced all 3 coil packs with no change.
Jan 9, 2010 at 8:23 PM
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MMPRINCE4000
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TCC clutch may not be disengaging, but a Snap On scanner should tell you if PCM is commanding lockup.

If still misfiring, may be bad cam/crank sensor, or possible fuel pressure problem.
Jan 10, 2010 at 7:55 AM
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SISSY03
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What would cause the fuel pressure problem? What should I check before proceeding. I have already taken my car to a shop and they have no answer for me. The only thing that was showing up on the snap on scanner was the TCC code and all the misfires when accelerating. I really do appreciate all your help and time trying to figure this car out. Im getting so frusturated with it at the moment I just dont know what to do. Thanks so much!
Jan 10, 2010 at 9:59 AM
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MMPRINCE4000
  • CAR REPAIR CONTRIBUTOR
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If TCC is problem, then they should repair it, but it could also be a fuel pressure problem (bad pump) or ignition (plugs, cam/crank sensor).

They should check all this out, especially if car is mis-firing.
Jan 11, 2010 at 8:34 AM