Alright guys, I have been a lurker on here and have had great success using the knowledge on this site to keep my baby running. I have a head scratcher now.

Just changed the pan gasket and rear main in my 01 XJ so decided to clean under the hood real good last night. I degreased it and washed it off with a hose. I noticed this morning after a couple of miles that it didn't want to shift real well and the temp was about 20deg cooler than what it usually runs. I stopped for some coffee and when I put it in park the temp almost immediately jumped up to 210 where it always runs.

I recently installed louvers and within a week we had a flooding rain and the TPS got wet. The shift systems were about the same so I put a new TPS in this morning and that didn't correct it. I have also read on here that a bad coolant temp sensor can cause some strange issues so I just finished putting a new one of those in also. Took her out for spin and the problem is still there.

I did notice that if I hold my foot in it at 3000 rpm's it will spit and sputter and a CEL will come on. I plan on running by the parts house and getting the code pulled but does anyone have any idea what I should be looking at. I am assuming I got something wet but for the life of me can't figure out why the temp reads fine in park but immediately drops when I put it in drive or reverse ???

 

Just noticed another thing, when the key in the on position but the engine not running the temp gauge reads correct. I can shift into reverse or drive (engine still not running) and the gauge immediately drops......

When i washed the motor I didn't use high pressure and tried to stay away from the ECU/MAP/IAC/TPS.

 

"I plan on running by the parts house and getting the code pulled but does anyone have any idea what I should be looking at."

It would be a waste of your money to guess without knowing the actual code(s).

 

Alright, pulled codes and it said TPS. Just put 3 brand new ones on it and symptoms don't change and it continues to throw the TPS code. Notices that temp gauge drops in D/R and reads correct in P/N. Any ideas?

 

Did you check to see if water leaked into any of the electrical connections?
Water + electrical = Bad

 

3 of the same brand?
Is the wiring in good shape?
Have you cleaned all the underhood grounds?
Are you willing to pop for a MOPAR factory TPS to see if it cures it?

 

Found the problem. Connector on ECU is cracked and it let some water get in. Had quite a bit of nasty stuff in there. Pulled it apart, cleaned it, packed with dielectric grease and she is purring like a kitten again.