Puddles Caused Engine To Go Nuts

I have a 96 XJ sport model with 4.0 and auto transmission. Last weekend I took the time to hit several large puddles (we rarely get rain here) and later that day the engine started acting up. I should mention that the entire engine got soaked due to splashing and the size of the puddles.

As of now, if I start it up it idles fine. I can put it in gear and it starts acting up. When coming to stops the idle will drop and the engine will die if I let off the gas. When accelerating it will go into a bad rev oscillation at 2500 rpm's if I try to accelerate at a normal rate. If I put the pedal to the floor it will skip right through this area, but the engine will not rev any higher than about 3500 rpm's, even if I am trying to pass. Instead it will accelerate through the gears as best as possible at 3500 rpm's. Also the cruise control will light up, but not do anything.

All of this is a surprise as the XJ has played in water and fowl weather before without any problems. Any ideas would be appreciated.

Thank you for your help!

Sounds like you screwed up the throttle position sensor (commonly affected by water.) You can remove it (it's mounted on the back of the throttle body exactly across from the center of the cam that all the throttle/transmission cables connect to, has 3 wires) and try putting it in the oven for a few hours at 150-200 degrees (NO HIGHER!) to see if you can dry it out, but you likely will need a new one.

Before you buy any new parts though, you'll want to hunt through the engine compartment and put dielectric grease in any connectors that appear to have water in them.

kastein said:

Sounds like you screwed up the throttle position sensor (commonly affected by water.) You can remove it (it's mounted on the back of the throttle body exactly across from the center of the cam that all the throttle/transmission cables connect to, has 3 wires) and try putting it in the oven for a few hours at 150-200 degrees (NO HIGHER!) to see if you can dry it out, but you likely will need a new one.

Before you buy any new parts though, you'll want to hunt through the engine compartment and put dielectric grease in any connectors that appear to have water in them.

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I'll give that a try then (the oven trick) as I've been looking at and checking vacuum hoses and the connection to the transmission. Hopefully not totally fried, they are about 50-80.00 from what I can find online. Though I may need to replace it anyways as the Jeep has developed a flat spot at about 2000-2500 rpm's when cold and it would hang there until the pedal was really pressed. Really annoying as pedal travel from 2-3k would only get 2k.

Would this also keep the transmission from downshifting and going to 4-5k for passing? Hopefully its all the same fix.

Thanks again!

96XJ9705 said:

Would this also keep the transmission from downshifting and going to 4-5k for passing? Hopefully its all the same fix.

Thanks again!

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Yes I had the same problem a few months back when I did a little engine cleaning. The shift points get screwed up because of screwed up readings from the TPS.

All symptoms you mentioned (except for the cruise control issue) could be caused by the TPS as mentioned. Concentrate on that.

Ok, trying to bake it today. If that doesn't work I'll go in and drop 75.00 for one. Turns out that the 96 uses the TPS from a 97. More of the mixed model year issue that Jeep had.

Well, baking didn't do it, but putting in a new TPS and unhooking the battery and reconnecting it has cleared it and it works again. Thanks for the help, I was worried I'd never be able to accelerate again.

96XJ9705 said:

Well, baking didn't do it, but putting in a new TPS and unhooking the battery and reconnecting it has cleared it and it works again. Thanks for the help, I was worried I'd never be able to accelerate again.

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Thought this might help, just in case: http://www.youtube.com/watch?v=WfrJWwKNvQY

joe_peters said:

Thought this might help, just in case: http://www.youtube.com/watch?v=WfrJWwKNvQY

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I was thinking more or less of just being in a lane without having to steer and brake with no power at every stop. That and the ability to squeal the tires again.

By the way, you were right about the rain:

http://www.youtube.com/watch?v=2KjF58a6V_s