theres this 94 bonneville that i want to buy and is thousands below the book value but since the guy lives near me he almost talked me out of it. he told me that the car stutters, hesisates and stalls while going up hills and traveling on the highway. He said he brought it to the dealer to get fixed and they replaced the computer which sounded like they were just trying to get money out of the guy. It seems that he thinks this is a serious engine problem and nothing else has been done to see what the problem is. Im thinking this is an easy fix but i dont want to get stuck with something that will cost thousands to fix. The altenator and the starter were also replaced but not because of this problem. The car also has 100480 miles. Any help would be greatly appreciated.

It could be something as simple as a good tuneup, but it could also be something more serious.

What I'd do if it was me facing this dilemma, is do a compression check. If both the wet and dry checks came out good, I'd probably buy the car. Borrowing a scan tool and checking that out might not be a bad idea, either.

Knock sensor

Wiring

I am betting if its not serious or maintenance based its something like that.

Coil pack?? My car (1992 SE) used to just stall out driving down the road when I would let off the gas. I checked the coil packs and it had cracked coils. Check to see if the black plastic coil covers are cracked at all. It allows moisture in and the spark gets messed up.

Coil pack troubleshooting in Techinfo.