TPS - Hesitation problem - 1994 Lesabre Buick

I had a problem with the TPS and replaced it recently on my Buick Lesabre 94 with the 3800 engine. My problems with tranmission shifting went away and everything was fine for the next 6 weeks then I had a transmission failure. Loss all gears except first gear. The car has 155,000 kms on it. Up until the TPS acted up I had NO PROBLEMS with the car since the 85,000 kms when I bought it. I had the tranny rebuilt and shortly thereafter had the same problem with the TPS. I chalked it up to a faulty part and replaced it again.

Since this install I am finding that the car when started cold (sitting over night) needs to warm up and until such times that it does it hesitates and backfires. It takes about a minute and after that it is fine. The gear shifting is slowly improving but not quite back to normal.

My car never needed to warm up prior to all these problems. You could literally start and go from the get go.

Any suggestions? Is there a proper way to install a TPS on my car and maybe I missed something? How is the best way to go about tackling this problem of hestitation on initial cold start? It seems like the ECU is adjusting everything on cold start, and as it slowly gets everything set up it begins to act normal. Until then it sputters if I put a load on the pedal.

HELP!

Did you check to see if it has set any codes? Autozone will read them for free. They will hook up an OBD II scanner and check it. The symptoms sound like it could be the TPS as it determines fuel delivery per the throttle valve angle (when giving it gas). Possibly, it runs poorly, sets the code and then runs better when reaching a default run value. I would check for codes first. I have never replaced the TPS in my 97 Lesabre, but I did take it off once to check it once. It was easy to remove, but had to use a GM star head wrench to take it off and put it on. There isn't much to it. Take off the wiring and remove the sensor. The TPS in the 97 doesn't seem to have an adjustment, but some of them must be adjusted. I don't think it would cause a transmission problem. It might be something else that has set a code.

Did you check to see if it has set any codes? Autozone will read them for free. They will hook up an OBD II scanner and check it. The symptoms sound like it could be the TPS as it determines fuel delivery per the throttle valve angle (when giving it gas). Possibly, it runs poorly, sets the code and then runs better when reaching a default run value. I would check for codes first. I have never replaced the TPS in my 97 Lesabre, but I did take it off once to check it once. It was easy to remove, but had to use a GM star head wrench to take it off and put it on. There isn't much to it. Take off the wiring and remove the sensor. The TPS in the 97 doesn't seem to have an adjustment, but some of them must be adjusted. I don't think it would cause a transmission problem. It might be something else that has set a code.


I do not suspect the TPS as it is new unless of course the TPS is not the exact correct replacement part and is functioning out of range thus sending initially incorrect information to the ECU and the ECU is having to calibrate it???? Not sure but I am edging towards maybe replacing hte spark plugs, then wires checking if it repairs itself. Right now it is just about 30 seconds of stumbling when starting on a cold engine that has sat for a few hours.

Interestingly you mention a GM tool. God I wish I thought of that because the first TPS I installed I took the whole throttle body off just to get at those two star headed screws. Thesecond I went in from the other side removing the EGR and thermostat housing. Second time was pleasant because I took the time to clean up the radiator system while waiting on the part to come in for the TPS.