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Old 08-18-2013, 08:53 PM   #1
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98 TJ rough idle Help!

I own an 98 TJ 2.5L 4 cyl. When started, and is idling the rpms drop really low and sometimes kills the motor. We know there is a small exhaust leak somewhere (seafoam test). Any other ideas how to fix the idle? I leave for college in a week and I want to take it with me.

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Old 08-18-2013, 10:05 PM   #2
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How many miles on it? Has the throttle body been cleaned? I have read that a dirty throttle body (including a AIC). give it a shot...

http://www.wranglerforum.com/f5/very...dle-52192.html

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Old 08-19-2013, 02:31 PM   #3
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It has like 140k miles and the throttle body has been cleaned but thanks for the link!
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Old 08-19-2013, 02:32 PM   #4
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Cps. Try to replace it- helped my idle and cutting off issues..
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Old 08-19-2013, 02:39 PM   #5
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Before replacling the expensive CPS unplug the TPS (throttle position sensor) and see if the problem goes away. If it does then your problem is the TPS
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Old 08-19-2013, 02:41 PM   #6
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True point- didmt think about that- cps is 89.00 so i would check that too
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Old 08-19-2013, 03:47 PM   #7
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Thanks guys. I will let you know how it goes
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Old 08-21-2013, 06:17 PM   #8
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We replaced the TPS and it didn't really help. We think it is the IAC giving us problems. When unplugging it (the IAC) there is no change in rpms.
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Old 08-21-2013, 09:10 PM   #9
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I just went through this very same situation and if I can throw my 2c in. I replaced the TPS with a non Mopar one - Problem still there. Switched it with a Mopar one - Porblem Gone. TPS exchange has to be genuine in my experience. See if you can grab one from a TJ or XJ thats original just to test the theory.
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Old 08-21-2013, 09:12 PM   #10
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By the way - I found this out after replacing all my sensors up and downstream as well as my headers.... Better to start repairs at the cheaper end of the scale..

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