2003 Pontiac Grand Prix Misfires or torque converter

SISSY03

MEMBER
2003 PONTIAC GRAND PRIX
6 CYL
FWD
AUTOMATIC
103,000 MILES

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.

Saturday, January 9th, 2010 AT 8:23 PM

3 Replies

MMPRINCE4000

MECHANIC
8,548 POSTS

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.

Was this

answer

helpful?

Yes

No

Sunday, January 10th, 2010 AT 7:55 AM

SISSY03

MEMBER
2 POSTS

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!

Was this

answer

helpful?

Yes

No

Sunday, January 10th, 2010 AT 9:59 AM

MMPRINCE4000

MECHANIC
8,548 POSTS

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.

Was this

answer

helpful?

Yes

No

Monday, January 11th, 2010 AT 8:34 AM