3800 rough acceleration after 50

[jason72]

i have had a problem with my gtp having rough acceleration after about 50 mph. when running for a long period of time the acceleration was really rough. when i made a stop and let the engin cool it was not to bad untill it warmed up again. i also had the fuel pump fuse blow the other day. if any one knows what is happing or if they have any ideas about the pleas let me know. or if you know of a good gm dealer to take it to as village pontiac gives me a line of crap.

Click to read more...

 

[xierxior]

is this after your car shifts into 4th? these cars turn into dogs in 4th gear and will barely want to accelerate on the highway if you're cruising at 50 for more then 30 seconds I believe the computer will go into a fuel savings mode and starts to lean the motor out if you had a bad o2 sensor or plugs you could be seeing these problems to.

do you have a scanner?

 

[jason72]

I have one of thoes scaners that uses a laptop I have checked for codes and there arent any. As for the rest of what that scanner can do im not sure what to look for.

 

[xierxior]

can you give me a better idea of what you mean by "rough" acceleration? you mean slow acceleration or like a mis fire? does it go away if you nail it? like part throttle only?

 

[LPSPEED2]

scan, check for KR or check for missfires, as those will both cause a rough high rpm. Also if you are getting missfires, check plugs for cracks, and wires for showing splices.