bucking/misfiring problem

howdy, group :)

i have an issue with my automobile. i purchased a 1992 buick lesabre v6 from my brother's brother-in-law about three months ago for a steal. very nice car and so far, it's done its job.

i recently had some tune-up work performed on it: new plugs, wires, and fuel filter. i had some drivability issues (some misfiring and overall not running as smooth as it should have been) so it was a good time anyway. the car ran very smoothly. however, i have begun to notice something "annoying".

what seems to happen from time to time is a bucking/misfiring problem. the car will be running well for a time, then suddenly it will start to "buck" as though is fuel-starved or misfiring. at this point, firmly hitting the gas brings it out of this state. it seems to happen erratically (sometimes it doesn't do it at all, other times it does it more than others). i can best describe it in detail like this:

i will be cruising along, at which point it will feel as though it is kicking into high gear. at this point the car runs a bit rougher, and the bucking begins. so, i drove the car in "regular" drive instead of overdrive (in this car, overdrive should be the normal "setting") to see what would happen. it seemed to run better, leading me to believe that the problem may be with the overdrive. i did also observe that occasionally while driving up a steep hill, the problem would occur.

it's hard to explain exactly when it occurs since it is sporadic. i dropped some "heet" in the gas tank in case water was in the tank, and have tried higher grade gas for the heck of it.

i have no other noticeable problems as the car has very good power, gets good gas mileage, and starts immediately but i know something is "missing".

any help would be greatly appreciated.

thank you in advance! scott :)

p.s. as a side note, is it safe to drive the car in "regular" drive as opposed to overdrive both on side streets and the freeway? just curious as i have a fairly long trip coming up very soon :)

Reply to
SJS
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My guess is the O2 sensor, but usually the check light appears on most cars if it buckles uphill. If you disconnect the O2 wires, you force it rich, by this you can tell it's the O2. DON't drive too long with disconnect O2 wires because you'll have problems. Rick

Reply to
Ricky Spartacus

one thing i forgot to mention. when the car is cold (usually only in the morning) the "service engine soon" light comes on and stays on for a mile or so, seemingly until the engine temperature is at somewhat normal operating temperature. it only happens when the car is very cold. maybe this is another clue.

:)

Reply to
SJS

With the car idling, take a screwdriver and with the plastic handle, tap the mass airflow sensor and see if it misses. That was a big problem with the

3.8 for a while. It won't "hurt" your car to drive it in 3rd gear, as opposed to overdrive. It may hurt your mileage. Actually, it is better for around town. Keeps the constant shifting to a minimum.

Reply to
Harry Balzak

Check and see what diagnostic codes are stored - look on my site below or

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for the procedure.

Reply to
Robert Hancock

i finally pulled the codes. the only one that came up was code 43: ESC circuit; knock sensor signal. not a clue what that is =)

Reply to
SJS

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