Buick issue on 94 Lesabre. I cant find it and I am stumped!!

[moparguy01]

my 94 Buick Lesabre is having abit of a issue. It hesitates under varying amounts of load, but it is always worse around 55-57 mph. It feels like your riding the bucking bronco.

heres the thing. the fuel pressure is good, so is the regular, the tps, o2, all of that checks out. The car throws no codes at all. Right now i'm just confused. does anybody have an idea what else might cause something like this and NOT throw a code? I just checked the motor mount and its weak while in drive under load, could something like that tweak the engine enough to cause a short in a wire or something like that and not trigger a code?

and no, putting a 440 in it is not a option at this point.

[no318]

my 94 Buick Lesabre is having abit of a issue. It hesitates under varying amounts of load, but it is always worse around 55-57 mph. It feels like your riding the bucking bronco.

heres the thing. the fuel pressure is good, so is the regular, the tps, o2, all of that checks out. The car throws no codes at all. Right now i'm just confused. does anybody have an idea what else might cause something like this and NOT throw a code? I just checked the motor mount and its weak while in drive under load, could something like that tweak the engine enough to cause a short in a wire or something like that and not trigger a code?

and no, putting a 440 in it is not a option at this point.

I would be REALLY surprised if it isn't an open plug wire.  Very typical on them to buck at 50-60.  Pull the wires off the coils and see if any are corroded.  Check that one first. 

[moparguy01]

They were all fine. Checked those this afternoon. none of them looked bad. I also ohmed out the plug wires, but didnt see anything out of the ordinary

[69-DodgeCharger]

I know the feeling youre describing by the 'bucking bronco' lol that is scary as hell. My 97 Cutlass got fucked up one day and I know this aint whats wrong on yours but on mine the head gasket blew. It leaked antifreeze/coolant all over the engine and burned over everything and just absolutely stank, it was like a sweet but sour smell. Everytime the car would come to an idle it would start shaking and shit and the check engine light wasnt on, but it was flashing at me instead lol so I brought it in to a mechanic and 4 days and $1800 later I had my car back in shape and have only had minor problems since. When I started up the car and took it home from the shop, there was just a huge cloud of smoke coming out of the exhaust and they said dont worry about it thats just the last of it burning off and they were right.

But as for your issue, I am clueless...just wanted to share the story of my car and that bucking bronco expreience

[Back N Black]

Is it a 3.8 liter ? I had the same symptoms with my Bonneville, It was the vibration dampener.Remove the belt and check for play in the dampener, its mounted in rubber and the rubber separates causing enough free play to throw off your timing.
Clear as mud, hope it helps.

[moparguy01]

Man this problem just stinks. I'm gonna start throwing some money at it and see if I can get some results. first step is plugs and wires.

so far ive had people think its secondary ignition system, some think its transmission issues, others think its motor mount issues, and now i get to add vibration damper to the list of stuff to check. I want my 68 coronet 4 door back. I knew what was wrong with that car......

[derailed]

Is it a 3.8 liter ? I had the same symptoms with my Bonneville, It was the vibration dampener.Remove the belt and check for play in the dampener, its mounted in rubber and the rubber separates causing enough free play to throw off your timing.
Clear as mud, hope it helps.

Had the same problem in my old 3.8 Will cause the car to buck really bad under load and run like crap. Mine was real bad, you didnt even have to pull the belt off to see it was wooped. I think they all had this problem back then and its where I would start. I picked up a new one for around $200 and it took about an hour to change.

[andy74]

Last one that i had a problem with like what you described it turned out that the damn fuel filter was partially clogged-worth the 12 bucks to check it out

[moparguy01]

it ended up being bad spark plug wires. Whats weird is that they ohm'ed out just fine. but i put new plugs and wires and it took care of it.

43 dollar fix. not terrible thats for sure.