i got a 91 grand prix with the old 3.1 mpfi and a 4t60 trans.... heres the problem i drove it earlier and it got up to 2500 rpms then bogged down to 2000 rpms then jerked back up to 2500 repeated this 3 or 4 times before i managed to pull off to the side of the road. it did it before shifting and after it shifted from 1st to 2nd. seems like whenever it goes above 2500 rpms it bogs down. and it jerks from 2000-2500 rpms wont go past 3000 rpms i know the car shifts at 3250 rpms. it barely made it into 2nd gear before i could pull over. had it towed to a shop and their looking at it. just wanna try and figure out what it could be... it doesnt seem like a slipping trans cuz its bogging down rather than the rpms going up. for a lack of better discription, it feels like you slamming on the brakes then flooring it over and over.
