Very slow...

Last night I washed down the engine and underneath the XJ. It started just fine and I drove home with no issues. Today it started ok but rev'd up and then went back down. At idle it wouldnt go below 1000rpm's. It runs fine, doesnt hesitate, or stumble, etc. And now it seems to be ok when I start it. It starts normal and idle is back to normal for now. Everything seems fine. Except when I try to pass someone or merge onto the freeway. I timed it on the way home from work tonight. Full throttle both times: 45mph to 65mph took 19 seconds. Then from 55 to 65mph took 10 seconds. Didnt kickdown but acted like it wanted to a few times. I turn the transmission shift switch a few times and it didnt matter nor did it matter after I exercised the shifter back and forth a few times. I thought maybe a vaccum leak but all my hoses seem to be on. I also thought maybe the TPS was starting to die. I did do a search and read some threads. Now I'd like to see what others might have to say.

Washing Engine Kills TPS

Washing the engine can easily result in a TPS dieing shortly therafter. I don't know why- they appear sealed- I guess not. The give-away was the accompanying automatic transmission weirdness: high idle issues and noticeable weirdness in auto tranny shifting indicates TPS, since it has inputs to both the TCU and engine computer.

Thats what I was hoping to hear. I am going to give it a couple more days before I pull it off and hook it up to the tester. I tried to wash that side of the engine as little as possible and even had the jet spray further away.
thanks for the feedback.

Yep, I’d bet that it is the TPS. When mine went bad it did the same thing and also had dead spots in the throttle. The TPS is very sensitive to water and they don’t like throttle body cleaner either.

well its been a few days.... still doesnt kick down when passing or stomping on the gas. there arent any dead spots... doesnt surge or hesitate, seems to start like it always has and runs good.. its just slow during acceleration... tonight on the way home from work I went ahead and shifted down to 3rd while merging onto the highway... it sped up rather fast... not as fast as it should... but I was able to merge and pass people as long as I shifted down manually... i exercised the tps again... looked for other problems... it idles fine, runs fine... just reminds me of driving an old 40 horse type II volkswagen. you can stomp on the gas as much as you want bt it aint going to go any faster.

Wiley Coyote said:

Yep, I’d bet that it is the TPS. When mine went bad it did the same thing and also had dead spots in the throttle. The TPS is very sensitive to water and they don’t like throttle body cleaner either.

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Yeah, some would say that you only need to spit on the sidewalk next to the Jeep and the TPS will start to throw wobblies. Before you go out any buy a new one, remove the connector and make sure that the connector itself and its contact points inside the TPS are dry. Then apply a thin smear of dielectric grease to those areas and hopefully the problem will be solved. Some water repelling spray applied to the outside of the connector and the three wires going to it wouldn't hurt either.