95 Bonneville 3.8 question

[sunkinboat]

idles fine and drives fine once I get up tp speed and set the cruise, but when I touch the gas and am accelerating it really hesitates and kinda jumps. It is also fine when I really get on it. Any idea what it could be? I spose I should just bring it in and have them read the code but I dont wanna spend the extra money if I dont have to. I was thinking maybe injectors or maybe an O2 sensor or something but I am not a profeesional mechanic. Let me know if you have any ideas.

[waskawood]

I had a 3.8 and when it would shift into overdrive it would shimmy. The mechanic said it was injectors or the transmission. I drove it for 2 years and it finally got so bad I couldn't drive it. Took it to another mechanic and he replaced 1 plug wire and it never did it again!!! May want to start there.

[john.wells]

Quote:

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idles fine and drives fine once I get up tp speed and set the cruise, but when I touch the gas and am accelerating it really hesitates and kinda jumps. It is also fine when I really get on it. Any idea what it could be? I spose I should just bring it in and have them read the code but I dont wanna spend the extra money if I dont have to. I was thinking maybe injectors or maybe an O2 sensor or something but I am not a profeesional mechanic. Let me know if you have any ideas.

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I really don't want to sound sarcastic or condesending, but more often than not people will spend WAY more money by throwing parts at a problem and spend WAY too many precious hours in the garage instead of on the water than if you had a scan done to nail down a problem. Granted, alot of garages will not be too willing to perform a diagnostic without the follow up work, but some will.

[hitthebricks]

Personally I like to bring the car to a local shop, ( not a Tires Plus, Firestone, Goodyear) some place with a real mechanic, have them diagnose the problem and call me to OK the repair, at that time I make the appropriate decision for my ability, time and cost as to who will do the repair. My wife had a 95 Bonneville, until my daughter totaled it, it was a great car. HTB

[Jeremy airjer W]

I'd have to agree, this one needs to see a good tech. The symptoms you describe could be any number of or a combination of failed components. It could be as simple as a tune-up or as major as a transmission.

Is there a check engine light? If night the likely hood of "codes" existing are slim are probably have nothing to do with your drivability complaint. There is no "magic machine" or "Magic computer" that figures this stuff out. There are diagnostic tools that help make an educated decision, but ultimately its experience/knowledge and a little talent that fixes problems like this!

I had a caravan a couple months back that had a similar symptom. Everything was fine until you did a light accel around 40 miles an hour. My gut feeling on the test drive was ignition. The symptom was so funky I didn't rule out the possibility of a transmission failure. Nothing I did could duplicate the symptom in the shop. I was becoming more convinced something was wrong with the torque converter after a couple more test drives. Finally I went with my gut and started a visual inspection of the ignition system and found the problem. The plugs where severely worn out. They never gave any other "normal" symptom for worn out plugs. It all made sense after that. The vehicle would misfire at light throttle around this speed because the torque converter locks up at this speed causing the heaviest load on the engine and the ignition system.