Could my TPS or IAC be causing a high idle?

Ejforan

Ejforan

TJ Enthusiast
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Joined
Jun 5, 2018
Messages
245
Location
Washington state
Hey all, just got back from a wheeling trip and while out there we came across a water crossing that was underestimated as seen below. Afterwards the jeep was acting funky no codes or anything idling around 2 and even 3k rpm we pulled the tps and it went right to normal so as far as I can tell thats what got some moisture into it. That caused a code but it went away on its own in a couple hours making me suspect the tps is still working. Idle has dropped down to around 1.5k fluctuating a bit and only while in park and probably neutral. I am hoping the pcm is just trying to recalibrate while there is still moisture but I was curious about others experiences similar to this. Completely driveable still but I could tell the computer was a bit confused to shift to first at a stop. Any and all input would be helpful. (The water was not nearly as deep as it looks it did not get past the tub except for a very small portion)

8B871821-8B2D-4A48-9A86-681390DB6F49.jpeg
 
Update: today I started the jeep up and it was still idling at about 2k rpm maybe a bit higher so I shut it off after a few seconds. I plan to clean the IAC and check vacuum lines as I have ready about hopefully it will be an easy fix whatever is causing it.
 
Ejforan said:
Update: today I started the jeep up and it was still idling at about 2k rpm maybe a bit higher so I shut it off after a few seconds. I plan to clean the IAC and check vacuum lines as I have ready about hopefully it will be an easy fix whatever is causing it.
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Vacuum could be the issue, but should give you a code. Check the linkage and spring at the throttle body for binding as well as the cable. Might be hanging open on you. Had that issue with an old carbed truck. If its not throwing codes I would check the easy stuff first. Air filter get wet? I would replace it.

Sell your jeep and buy a submarine :p
 
AMS417 said:
Vacuum could be the issue, but should give you a code. Check the linkage and spring at the throttle body for binding as well as the cable. Might be hanging open on you. Had that issue with an old carbed truck. If its not throwing codes I would check the easy stuff first. Air filter get wet? I would replace it.

Sell your jeep and buy a submarine :p
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No need to sell it if it already is one!
I went to talk with my jeep mechanic and he has had tons of these come in after a hard water crossing. Enough water can get into the sensor permanently shorting it but only by a bit so the voltage is the same as whatever it would normally be at with the pedal down a bit. Will be replacing the tps with a mopar replacement and clean out my IAC and most likely the whole throttle body since I am already working on it. Will get back with results after I replace it. Most posts I have seen had said the TPS usually causes erratic rpm so I was suprised when my mechanic said it was common for the TPS to be the culprit.
 
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Once a TPS gets anything inside, scraping debris from its variable resistor or water, it's toast. I'd go Mopar or at least NAPA's best quality. Definitely don't go with any cheap store brands like Duralast from Autozone.
 
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Jerry Bransford said:
Once a TPS gets anything inside, scraping debris from its variable resistor or water, it's toast. I'd go Mopar or at least NAPA's best quality. Definitely don't go with any cheap store brands like Duralast from Autozone.
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I am for sure going mopar. Is there any mopar oem site better than the rest? It is 65 from any of them, 95 through official mopar and my dealer quoted 130. Is there any reason to steer away from moparfactoryparts or anything similar?
 
Ejforan said:
I am for sure going mopar. Is there any mopar oem site better than the rest? It is 65 from any of them, 95 through official mopar and my dealer quoted 130. Is there any reason to steer away from moparfactoryparts or anything similar?
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Amazon is also 95 and will take a few weeks to come in and I do not want to wait that long since the jeep is my daily.
 
Found a mopar tps off rockauto and just installed it today. The jeep runs beautifully now. The previous sensor was a cheap autoparts store one and I am surprised its gotten through the 30k miles I have had the jeep with as much water as I have gone through. I hope this may point others with the same problem in the right direction!
 
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