I have a 1994 Buick LeSabre. I keep this car clean inside and out and including the engine. I have noticed that after I clean the engine my check engine light comes on. Have tried to pull codes with scan tool from local parts store, but no luck. The engine starts fine after cleaning, but I noticed that it does not shift properly. 1st gear fine, 2nd gear for a moment then 3rd is normal. Its as if 2nd is skipped. This will go on for several days and I can stomp on the gas, but no passing gear kicks in. Once the check engine light goes off after 6th day, engine runs normal and all systems are good.


Another problem that has occured is my engine will idle high after cleaning. I unplugged the TPS and it idles back to normal, but again same symptoms as above, no passing gear, but 2nd is normal.


I am afraid to replce the TPS until I know that is the problem. Can anyone help?

 

BY clean do you mean WASH? I suspect water is getting to something.. I wouldnt use water and just blow around and wiggle stuff.. Vaccuum hose maybe but.


Try someone wetting certain areas while watching the dash..


Maybe you can find a TPS from a Junk Yard.

 

The old trick to locating vacuum leaks is to start the engine, and spray carb cleaner (carfully, using the little straw) on the vacuum lines. I would start with the connections, because that's where most failures occur. The engine revs will change (higher) when you seal the leak briefly with the carb cleaner. Best to do this on a not-too-hot engine, and don't spray the stuff on the exhaust manifold!

Vacuum hose is cheap, and if the car is old, or operates in a high stress environment (like FL hot weather), be a sport and change 'em out.