Jeep Wrangler Engine Troubles

monkeyman1018monkeyman1018 Member Posts: 2
I own a 2000 TJ 2.5L 5sp. I recently did a little mud bogging and found some problems afterward. The next time I turned it on, it idled at 1500 rpm. Later, on the highway, the check engine light went on and if I pressed more than half throttle, the engine would stutter badly. After a time, the idle returned to normal, the stuttering stayed, and power delivery from a standstill is rough.
Can anyone help with a diagnosis or solution?
thanks alot, Joe


  • mac24mac24 Member Posts: 3,910
    Two possibilities come to mind. First is that you've got water in the TPS which is now failing and needs to be replaced.
    Second, you may have got water in and around the coil rail which is now shorting out. If so you need to remove it, then thoroughly clean and dry both it, and the exposed heads of the spark plugs.

    Before you do anything else though, check for codes which will point you in the right direction.
  • erickplerickpl Member Posts: 2,735
    I had the exact same problem after going through some mud. It was the TPS. $53.00 at Autozone and 10 minutes in the parking lot (7 of that was looking for the right size torx bit in my toolbox) and I was good to go.

    I have a 2.5L also. It'll be easy to swap, but you need to take off your air tube first to get easier access.

  • monkeyman1018monkeyman1018 Member Posts: 2
    Thanks so much guys, you were right on with the TPS, as the guys at autozone pulled a code for a faulty TPS. I replaced it (finding the right torx bit DID take forever :)), but upon taking it for a test drive, found that nothing had changed. After I lift off the throttle, the rpms drop rapidly almost to a stall, and it's still rough when you push past half throttle. :(
    mac24, I do not think that my jeep is equipped with a coil rail, as there is a distributor cap with wires that connect directly to the spark plugs. Should I replace the wires or plugs or just dry them out?
    Thank you!
  • erickplerickpl Member Posts: 2,735
    Open up the distributor cap and clean it out. If there is moisture, spray some WD-40 (that is what it was SUPPOSED to be used for - water dispersement). You may have some trapped in there too. And it is easy to do.

  • ironhossironhoss Member Posts: 1
    4.0 motor stumbles ,pops,backfires,starting out down the road,give alot more gas it will go......
  • jarheadvetjarheadvet Member Posts: 1
    i have a 4.0 that #3 and 4 fuel injectors do not get signal to open all other injectors work fine,does this sound familiar to anyone?
  • kidstoyskidstoys Member Posts: 5
    Hi I have a 1993 Jeep Wrangler with a 2000 year 6 cylinder motor, Automatic transmission, California emissions. The wiring harness is formed from both years and ebay purchases. I narrowed down my wiring problem to the shut down relay. It is on prior to starting. Then it stays off once the key goes to the start position. The circuit does not re-energize until a couple of seconds after the key is released, and the engine stops running. I'm sure it is PCM related as the PCM controls the shut down relay. I attached a DTC ODB tester. Found codes for O2 Sensors. Added relays for the sensors cleared codes. That error code is gone. On one occasion I checked DTC codes and found a “P1686” no response from SKIM code. Cleared the code at the time and it has not returned since. The wiring harness contains no Security Key Immobilizer Module (SKIM) or Air Bag Control Module. Vehicle starts runs a few seconds and shuts off. Currently no ODB error codes show up during this cycle.
    The P1686 code relates to the SKIM it is an added option.
    Does anyone know if a DRB III unit can reprogram the PCM for SKIM does not exist? Are there any aftermarket ODB units that can do the same type of programming? Are there any other options to get around this error condition?
  • mac24mac24 Member Posts: 3,910
    Does anyone know if a DRB III unit can reprogram the PCM for SKIM does not exist? Are there any aftermarket ODB units that can do the same type of programming? Are there any other options to get around this error condition?

    No, unfortunately it can't. All diagnostic paths eventually lead to 'Faulty SKIM - Replace' or 'Faulty PCM - Replace'.

    While there are solutions for other vehicle's PCMs, such as EFi Live, there's nothing I know of for the Wrangler; there's just not the market for it.

    The most practical solution is to install a SKIM in the harness by the column, and tape a matching PassKey to it (or install a cylinder to match the key and use it as normal).
    The lack of an airbag module will continue to throw a code but won't cause any drivability problems.
  • kidstoyskidstoys Member Posts: 5
    Thanks Mac, Good answer... I also got to thinking that if the Security Key Immobilization Module was an option on the 2000 year Jeep. Maybe I could purchase a new PCM and have it programmed with all of the rest of the Jeep's features and leave out the SKIM's as an optional feature. It looks like 2000 was the first year the SKIM's was used. Possible ???
  • mac24mac24 Member Posts: 3,910
    No, the SKIS (Sentry Key Immobilizer System) was an option from '98 on; I have it on my '99.
    The reason I suggested adding a SKIM + key was that it might be easier and cheaper to find than a PCM. However, it would still have to be matched to the PCM with a DRBIII.

    A new PCM is an option, as is one from a '97 before the SKIS was introduced.
    The only problem with a '97 is that it's OBD system is unique to that year, kind of an OBD 1.5. :shades:
  • kidstoyskidstoys Member Posts: 5
    Let say the least expensive way to get around my staying running issue is to install the SKIS system. What vehicles, years would I have to choose from that have the SKIM (Security Key Immobilizer Module) compatible with the PCM (Power Control Module) that I have from the 2000TJ ??

    Shy of changing out my 1993 steering column how would I set up the module antenna and key to work together? I haven't seen the wiring diagram for the antenna. The wiring diagram that I have shows the module with connections to the data set ,ground, and PCM.

    I may get a better idea of what I'm dealing with once I get into taking one out of a vehicle at an auto recyclers yard. I hope to get lucky and get a system supplied with two ignition keys. But, if you have an idea on compatibility that would be very helpful in my search.

    Thanks for your time...and replies
  • mac24mac24 Member Posts: 3,910
    The SKIM plugs in to the harness on the column, which means you'd need the body harness if you don't already have it. A SKIM different to the original needs to be authorized by the PCM which is accomplished with a DRBIII.
    I don't think the year of the SKIM matters but I'm not 100% sure of that.

    Maybe another PCM (secondhand) would be easier if you can get one from a vehicle without SKIS as original equipment?
  • kidstoyskidstoys Member Posts: 5
    mac24, Thanks for your help. I finally have the 1993 Jeep YJ running with the 2000 Jeep TJ 4L motor, auto transmission, transfer case and a few other items in it. The only major hitch was the PCM from the 2000 was indeed looking for the SKIM module. The least expensive and sure cure was to send the PMC to Auto Computer Exchange in Florida. After making a phone call to their shop I drafted up a note with an explanation of my predicament. Boxed up the PCM along with the note and sent them their way. The $150 charge saved a lot of guess work and searching for something that may or may not work. They reprogrammed the PCM to not scan for the SKIM module. I just received the updated PCM unit back (about one week turnaround). Once installed the 1993 fired right up and stayed running as it should.

    Today I was in ordering some other parts at my local Jeep dealership and I went over the story with the counter person. He said the dealer parts department uses the same place for PMC reprogramming.
  • mac24mac24 Member Posts: 3,910
    He said the dealer parts department uses the same place for PMC

    Good find! It's funny that the dealer uses them too.
    Speaks volumes for where Jeep is now at. :sick:
  • musicalleymusicalley Member Posts: 1
    My Daughter just bought a 1993 Wrangler..6 cly and auto trans. When she pulls up to a stop at times the engine stalls ( shuts down ) and check engine light at times but not always will light up. She has taken it in 3 computer codes are showing up. Any ideas would be great Thanks,
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