surging especially on hills

[Gina Fink]

On a trip from Michigan to VA, my Buick 1994 LeSabre started to surge, especially when going up a hill. It sort of surges and then backs off. We had a computer print out done and it said there was vacuum leak in a/c system. we replaced the servo in the a/c and topped up the antifreeze. That did not do anything for surging. Replaced all the sparkplugs and wires.

Any idea what would cause the serging? Maybe fuel injectors?

[auto trainy]

If you haven't already done so replace the fuel filter and have fuel pressure test done,also check the vacuum at the fuel pressure regulator for starts.

[imidazol97]

Originally Posted by Gina Fink

On a trip from Michigan to VA, my Buick 1994 LeSabre started to surge, ....That did not do anything for surging. Replaced all the sparkplugs and wires.

Any idea what would cause the serging? Maybe fuel injectors?

I hope the wires were replaced with original equipment or a duplicate like NAPA's Original Equipment quality. I had replaced wires on '93 with Pep Boys and then replaced them again after I learned the car is sensitive to having the right wires.

But I had a '93 with a surging when torque converter was locked up and it was under light load when it was hot. Such as a slight upslope after a 45 mph merge onto an interstate and trying to speed up to the 60 mph of the typical traffic.

I thought it was EGR-related. I fiddled with it. But then later there was a PROM update for the computer that adjusted the speeds for locking up the torque converter. It wouldn't let the torque converter lockup (it was the 100% lockup type) until a higher speed and you didn't feel the uneveness of the motor at the lower speed under load. The PROM may have adjusted mixtures also. Later LeSabres have a slipping torque converter lockup that smooths out the vibrations.

If it doesn't do it when the brake pedal is slightly depressed which keeps the torque converter from locking up at the same speeds or slightly lower, I'd suspect that is what you're feeling.

[Gina Fink]

Thanks. I used Buick wires and high quality spark plugs. Will check the Torque control

[Gina Fink]

I had the fuel filter replaced, but didn't have the pressure check done. Will have that checked when I check the torque control. Thanks for your input