cruiser54

CPS will cause a no start, but not rough idle. Have you ever cleaned the throttle body and IAC?

Try this. Start it. It is ticking. Shut it off for 10 seconds. Start it back up. Is the tick gone? FWIW, Marvel Mystery Oil added to the oil in place of one quart of motor oil works well to clean lifters. What brand oil filter are you using?

CRUISER'S MOSTLY RENIX TIPS IMPROVING THE INSTRUMENT PANEL GROUND NOVEMBER 17, 2015 SALAD 27 COMMENTS The ground point for the complete instrument cluster on your XJ or MJ is located up under the driver’s side dash. If you lay on your back and look up under there with a flashlight, without wearing a hat, you will see a black wire attached to a shiny piece of metal almost directly above the hood release knob. The screw will have either a ¼” or 5/16″ head on it. This ground point is responsible for handling the ground circuit for the following items: Dome lamps, seat belt and key warnings, transmission power/comfort switch, wiper switch, headlamp switch and delay module, fog lamp switch, cargo lamp switch, all instrument panel grounds and illumination, power windows and door locks, cruise control dump valve, and a few more things. The problem is that where the ground point is located does not share good contact with the chassis where the ground should be. The solution is simple: Make up a jumper wire with #10 gauge wire about 10″ long. On one end, crimp on a ¼” round wire terminal. On the other end, crimp on a 3/8″ round wire terminal. Remove the screw from the existing ground wire and attach the small terminal of your jumper so that the original wire and your new jumper share the same attaching point, one over the other. Look above the driver’s side plastic kick panel just forward of the top of the hood release knob. You will see an 8mm stud there. Attach the large terminal end there with a washer and nut over it tightened securely. Use a coating of OxGard at all ground contact surfaces when attaching the screw and nut. **Special note for Comanche owners: Make your jumper wire 12″ long and attach it on the driver’s side kick panel close to the fusebox on the 8mm stud.**

Here's something you all should do at some point. CRUISER'S MOSTLY RENIX TIPS IMPROVING THE INSTRUMENT PANEL GROUND NOVEMBER 17, 2015 SALAD 27 COMMENTS The ground point for the complete instrument cluster on your XJ or MJ is located up under the driver’s side dash. If you lay on your back and look up under there with a flashlight, without wearing a hat, you will see a black wire attached to a shiny piece of metal almost directly above the hood release knob. The screw will have either a ¼” or 5/16″ head on it. This ground point is responsible for handling the ground circuit for the following items: Dome lamps, seat belt and key warnings, transmission power/comfort switch, wiper switch, headlamp switch and delay module, fog lamp switch, cargo lamp switch, all instrument panel grounds and illumination, power windows and door locks, cruise control dump valve, and a few more things. The problem is that where the ground point is located does not share good contact with the chassis where the ground should be. The solution is simple: Make up a jumper wire with #10 gauge wire about 10″ long. On one end, crimp on a ¼” round wire terminal. On the other end, crimp on a 3/8″ round wire terminal. Remove the screw from the existing ground wire and attach the small terminal of your jumper so that the original wire and your new jumper share the same attaching point, one over the other. Look above the driver’s side plastic kick panel just forward of the top of the hood release knob. You will see an 8mm stud there. Attach the large terminal end there with a washer and nut over it tightened securely. Use a coating of OxGard at all ground contact surfaces when attaching the screw and nut. **Special note for Comanche owners: Make your jumper wire 12″ long and attach it on the driver’s side kick panel close to the fusebox on the 8mm stud.**

HOrnbrod Moderators 20.2k Location: Sweet Home Alabama Posted November 21, 2016 New members to the forum, and some longtime members too, post technical questions in this forum but do not provide specifics of the MJ they are referring to. Like: Year of Manufacture Engine Drivetrain Body Style Etc., Etc. These details are necessary for responders to accurately answer your questions without guessing or having to ask what are the specifics of the MJ you are referring to. You can add these details easily and permanently by creating a signature or adding your truck details to your existing signature. Here's how to do it: 1. Click on the upper RH icon to open the drop-down menu 2. Click on Account, then Account Settings 3. In the Settings menu click on Signature 4. Compose your signature, or add to your existing signature 5. When complete, click Save

It would stand for all of them I guess.

Haha!! I knew one of you guys would chime in.

I don't know what the actual failure is. Someone versed in electronics would have to tell us that. Good rule of thumb regarding junkyard parts. Musta been running to get into an accident. If you can get an 87 or 88 for next to free, yes, grab it.

You folks who visit junkyards need to snag all the Renix ECUs and TCUs that you can. TCUs are starting to fail at an increasing rate. ECUs not so much, but grab what you can. They don't make them any more. If you have an 87 or 88, Grab an 89 or 90 ECU for your rig and save your old one as a spare. More horsepower BTW. 87s had a funkier shifting ECU program. An 88 to 90 is an upgrade. __________________

Wanna get rid of that kludgy switch?

It would be a great opportunity to remove the clutch pedal and reinforce it where the weld tends to break.

New members to the forum, and some longtime members too, post technical questions in this forum but do not provide specifics of the MJ they are referring to. Like: Year of Manufacture Engine Drivetrain Body Style Etc., Etc. These details are necessary for responders to accurately answer your questions without guessing or having to ask what are the specifics of the MJ you are referring to. You can add these details easily and permanently by creating a signature or adding your truck details to your existing signature. Here's how to do it: 1. Click on the upper RH icon to open the drop-down menu 2. Click on Account, then Account Settings 3. In the Settings menu click on Signature 4. Compose your signature, or add to your existing signature 5. When complete, click Save

Why not an 8.25 out of an XJ?

Ooooh, it's a limited slip!!

I slept in my car overnight in Ely 43 years ago, waiting for a gas station to open in the morning.

Haha!!! Nice research on your part.

How fun!!!

You could remove the EGR at some point to check for slight leak by blowing through it.

Good idea. Disconnect the vacuum to the EGR and plug it. See what happens. Keep in mind though that your EGR may not be closing completely causing a hidden vacuum leak. Have you ever snugged up your intake manifold bolts? cap and rotor replaced or not?

What did you replace?

How about a relay to the main power circuit of the blower motor?

I know the 3.7 and 4.7 are fussy about the oil used and the intervals that the oil is changed. I'm betting you are okay in that department.