95 LeSabre tranny help

[emilys granpaw]

my 95 LeSabre has started to feel like it has a miss on a cylinder; however,when I down shift from overdrive, it smoothens right out.I was wondering if anyone else has had this problem with thier LeSabre? Appreciate any feedback on this problem. Thanks

[imidazol97]

Originally Posted by emilys granpaw

my 95 LeSabre has started to feel like it has a miss on a cylinder; however,when I down shift from overdrive, it smoothens right out.I was wondering if anyone else has had this problem with thier LeSabre? Appreciate any feedback on this problem. Thanks

If it's occurring in lockup torque converter in 4th gear at about 50 mph and at slight load (slight uphill) or slight acceleration, I'd suspect spark plugs and wires. You don't indicate how many miles are on the car. And have the wires and plugs been replaced. Stick with original equipment brand plugs for best results and use original replacement quality wires such as Belden that I got at NAPA the last time I did my car. Don't go for any fancy color wires, e.g.

If it's something else breaking down in the ignition coils that will be more difficult to check. I assume the simplest explanation first.

There was a problem on my 93 leSabre with a similar roughness in that mode, rather than the feeling of a miss. It was fixed with a new PROM for the computer after a while. It changed the speed for the torque converter to lockup so that you didn't feel the roughness from the motor through the solid connection--the torque converter was in fluid slip mode. It also changed the fuel settings slightly from what I could tell. But the torque converter didn't lockup until about 53 or so instead of the 48 I think it would lock up in 4th gear. Good luck.

You might have it scanned at Autozone for a miss code. You might get a random miss or a specific cylinder miss code.

[Blue Bowtie]

To test the TCC lockup theory, instead of shifting from OD, lightly tap the brake pedal to briefly unlock the TCC.

[imidazol97]

Originally Posted by emilys granpaw

my 95 LeSabre has started to feel like it has a miss on a cylinder; however,when I down shift from overdrive,

Can you create the same miss in 3rd with the Torque Converter Clutch locked up at about 35 mph or less by going up a steeper slope to generate some pull? I would suspect you can't do that because the gearing is lower and doesn't load the motor as much despite a hill without releasing the clutch.


Is the miss completely regular like an actual plug or wire would be? Or is it erratic?