Seafoam clean now idle at 1000
#16
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Year: 1988
Model: Cherokee (XJ)
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I couldn't decide which suggestion was goofier, this one or the next one. So I decided to delete this one.
Last edited by dmoe69; 11-16-2023 at 09:06 PM.
#17
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Year: 1993
Model: Cherokee (XJ)
Engine: 4.0
#18
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So yesterday I went over the TPS again, all reading were correct 4.89 input .83 output 17%. I did an OHMS reading on the CTS and it was way off so I replaced that, it runs noticeably better on the road, but the idle is still at 950. When I was going over the TPS turning it clockwise did not lower the RPMS at all, but counterclockwise did raise the RPMS. When it is at spec readings it looks to be about midway between the rotation slots. Could it just be a bad TPS even though the readings are good, any other thoughts before a buy that (its a little of a salty price)?
#19
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Year: 1988
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What is your ohms reading between the b terminal of the TPS connector and the negative on the battery? - And forgive the dumb question, I should have done the math, and seen that .83v is 17% of 4.89v...
#20
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The OHMS shows .05 and no fluctuation anywhere through the loom to the C101. I had the loom completely apart over the winter soldered the ground splice and completely re-loomed.
#21
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Year: 1988
Model: Cherokee (XJ)
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You've done all the right stuff with your grounds and splices. I've had idle drift up with bad grounds, which were immediately corrected just by cleaning the grounds. It is obviously odd that the high idle would start after cleaning with Seafoam, especially from the ingestion point you picked. A newly exposed vacuum leak could be a cause, but rather unlikely. I recently had a high idle issue that I resolved with an NOS MOPAR TPS (at least they sold it as NOS in an old original box). That cured the problem. I have a REM installed on my '88 XJ. It was odd that the REM would show the ECU was seeing 17% voltage, but the throttle would show "Part" when the idle would stick high. I adjusted the TPS down to as low as 13%, which the REM would show, but when the idle went high the REM would still show the throttle at "Part". Once the MOPAR TPS was installed with the voltage adjusted at 17% the throttle shows "CLSD" and the idle slows to normal within a few seconds of start-up.
#23
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I found a NOS Mopar TPS for a good price, it is for a RENIX. My question is it isn't just the 3 prong connection, it has both styles of plugs (3 prong man. and 4 prong auto). Will it work and I just disregard the 4 prong connection.
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cruiser54 (11-23-2023)
#24
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Last lines of Cruiser54's tip 8 on TPS testing and adjustment. "For those with a MANUAL TRANSMISSION–the TPS for the manual transmission XJs is stupid expensive. You can substitute the automatic transmission TPS which is reasonably priced. The square 4 wire connector is just not used."
The following 2 users liked this post by dmoe69:
cruiser54 (11-23-2023),
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#25
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Just to close this out, after all this time I was messing around under the hood and pinched off my rear CCV hose that had been custom installed by me with 1/4" hose and the idle dropped. I had got an acceptable grommet for the valve cover but it was not restricted and I had just ran a 1/4" hose to the intake (that was the mistake). I have now ran the proper rear CCV line assembly and she purrs like a kitten at 750rpm solid.I also have all new sensors either Denso or NTK and all of the originals saved.
The following 2 users liked this post by Phydeaux33:
dmoe69 (03-03-2024),
Offroadnutz (03-03-2024)
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