Jim Grant's Tech Tips

'93 Buick Le Sabre, Bucking and Jerking

Q: My '93 Buick Le Sabre starts bucking and jerking at 40-50 mph, at normal operating temperature. This mostly occurs on a slight uphill, but not all the time. When I ease up on the gas and reapply the pedal fast, the problem seems to go away. It repeats after a while and it is not constant.

- Peter D.

A: It almost seems that you may have the start of an ignition problem making itself known. The early stages of a failing ignition coil, spark plug or spark plug wire can often cause a jerk or bucking feeling. What is neat about this problem is the way that you can almost drive around the condition. What I mean by that is, all you have to do is change the position of your foot on the gas pedal, move the automatic transmission shifter from the overdrive position down to third gear or even lightly touch the brake pedal without moving your foot on the gas pedal. Some diagnostic time with the ignition system should provide the answer and result in a solution to your bucking/jerking Buick.