1996 Jeep Needs New PCM

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    • 1996 Jeep Needs New PCM

      I'm at the breaking point with my beloved Jeep. Within the past month I purchased 4 new tires and rotors, new bearings, and now it's cutting out at idle and stop signs, sometimes in busy traffic. Purchased new alternator last year. Car starts back up. Garage says that they can't get a read on the PCM. 130,000 miles. Is it time to say goodbye? Body is in great condition - garaged and mostly city driving, but I've recently been driving to the Catskills. I've read the reconditioned PCMs are not reliable at all and new ones are hard to get and, if i could, are very expensive. On a separate note - if I decide to buy another Jeep, can anyone recommend which is best for great visibility, mountain driving, good in snow, and whether or not it makes sense to buy new or used? No off-roading, but the house in the Catskills is on a very poorly maintained road - steep, rough dirt and rocks. I live in NYC but my siblings live in Wilmington. I got the car from my brother, who was leasing it and pretty much gave it to me about twenty years ago. (He's a very nice brother!) Met a guy with a Delaware Jeep t-shirt a few years back, so I figured I'd reach out. Thanks!
    • I'm going to say NO, you don't need a new PCM. Idle issues, and issues of stalling while coming down from higher RPMs (coming to a stop light or sign) can be caused by other things.
      1. the IAC (idle air control) sensor could be gunked up or need replaced. This bolts onto the side of your throttle body. Easy to removed, clean up, and install.
      2. While you're at it, pull the throttle body and give it a good cleaning too
      3. How about your vacuum lines and their connections? The Fuel pressure relief valve vacuum line runs off manifold vacuum.
      4. Another possibility "might" be the temperature sensor that tells the computer how to set the fuel mixture (works like a choke sort of)
      So don't give up hope yet. I bet it's something simple.

      youtube.com/watch?v=_2VDYu5144k
      youtube.com/watch?v=fpYSfvAxSkk

      I personally like the 2nd video better because the girl explains things really well and you have to give her props for doing it in sub-freezing weather.
      :spinrhead: ...covfefe... :spinrhead:

      The post was edited 2 times, last by Slimer ().

    • its a bad sensor somewhere. U can read the codes by turning the key on and off 3 times and reading the odometer. Im sure there is a vid on google. The 96 is an oddball year being the first year of obd11.

      It sounds like the iac, but could also be the cps or tps and even the vss sensor. Many times these wont even trip a code.
      '88 YJ with not much '88 left. :)
      Team Mall Crawler #609
      Werock Stock Class we-rock.cc
      Werock '06 - 2nd East Coast, 5th overall Werock '07 - 3rd East Coast Sponsored by: The Drive Shaft Shop driveshaftshop.com Delaware Jeep Assoc. delawareja.com
    • Yup. Mechanic got some codes off of the PCM - apparently there were some loose or corroded wires - got that working and wants to replace the crank shaft position sensor, the knock sensor, the distributor rotor, the distributor cap, and a new air filter. Given that I just put new tires and new rotors on the car, and the alternator is only a year old, I'm inclined to do it. Please tell me I'm not crazy. Thanks!
    • there is no knock sensor on a 4.0l motor. Not a bad idea the replace the crank positon and distributor sync sensor. Parts should be under $100. But if it starts then they r not really needed just preventitive maintenence. Cap, rotor, plugs and wires would just be tune up parts and might be needed. U r not crazy u just need some maintanence.
      '88 YJ with not much '88 left. :)
      Team Mall Crawler #609
      Werock Stock Class we-rock.cc
      Werock '06 - 2nd East Coast, 5th overall Werock '07 - 3rd East Coast Sponsored by: The Drive Shaft Shop driveshaftshop.com Delaware Jeep Assoc. delawareja.com