86 TA Hesitates On Acceleration
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Car: 1986 Trans AM
Engine: LG4-305-Edelbrock Intake/Q-Jet Carb
Transmission: Automatic
86 TA Hesitates On Acceleration
Greetings All.
My 1986 TA with 305 CU 5.0 L engine with 4 bbl carburetor hesitates off the line. I can start out rolling to about 10 mph and 1000 rpm and then the more gas I give it the engine hesitates and bogs down and I have to pump the gas so it does not stall. Once you get up above 1500 rpm acceleration is smooth and powerful. Condition is much worse when cold and get better and less of a nuisance as engine gets hot.
One thing that also occurs is after moderate to heavy acceleration and then coming off the gas my Check Engine light comes on. After coasting awhile it goes out. Usually within 15 seconds.
Since I just acquired this car in California I had to get it smog checked. The car had been setting for 10 years, was started once a month but not run on the streets. When I first got it is did smoke a lot and failed smog horribly. The Previous Owner had indicated that the engine had gone through a rebuild prior to be taken out of service but sitting for 10 years cannot be good for the rings.
Nonetheless my mechanic gave the car an oil change(synthetic oil), new spark plugs, PCV valve, adjusted the engine timing and installed a new Bosch O2 sensor, which according to him the old one had been broken off and was not even installed, the car barely passed smog.
It does seem to run better and smokes only a little when started, I still have the hesitation problem and the Check Engine light.
Please let me know what progressions I should go through in order to debug this condition and correct what seems a very bothersome but common problem according to the other posts I see.
Thanks for everyone's assistance.
Big Ed
eca1987
My 1986 TA with 305 CU 5.0 L engine with 4 bbl carburetor hesitates off the line. I can start out rolling to about 10 mph and 1000 rpm and then the more gas I give it the engine hesitates and bogs down and I have to pump the gas so it does not stall. Once you get up above 1500 rpm acceleration is smooth and powerful. Condition is much worse when cold and get better and less of a nuisance as engine gets hot.
One thing that also occurs is after moderate to heavy acceleration and then coming off the gas my Check Engine light comes on. After coasting awhile it goes out. Usually within 15 seconds.
Since I just acquired this car in California I had to get it smog checked. The car had been setting for 10 years, was started once a month but not run on the streets. When I first got it is did smoke a lot and failed smog horribly. The Previous Owner had indicated that the engine had gone through a rebuild prior to be taken out of service but sitting for 10 years cannot be good for the rings.
Nonetheless my mechanic gave the car an oil change(synthetic oil), new spark plugs, PCV valve, adjusted the engine timing and installed a new Bosch O2 sensor, which according to him the old one had been broken off and was not even installed, the car barely passed smog.
It does seem to run better and smokes only a little when started, I still have the hesitation problem and the Check Engine light.
Please let me know what progressions I should go through in order to debug this condition and correct what seems a very bothersome but common problem according to the other posts I see.
Thanks for everyone's assistance.
Big Ed
eca1987
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
When the SES light comes on, a trouble code is stored in the computer. You need to retrieve the trouble code(s).
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305, 86, acceleration, carb, carbureted, carburetor, cold, engine, hesitates, hesitation, lg4, stalls, trans