cruiser54

Upgrade the harness. I think it's more the miracle you're looking for. I installed just the harness on my wife's and son-in-law's XJs. Massive improvement. Me, I ordered up Autopals off ebay for $50 delivered, and I had some 90/100 bulbs in the garage, so I did both the harness and the headlamp upgrade. I was anticipating upgrading the other 2 Jeeps from their Halogen bulbs to Autopals, but said screw it. They work about 30% better than the stock headlamps with only the harness.

Fine. Then the advice above applies. Start at the top using a flashlight and let us know what you see.

Gotta be tomorrow somewhere. If the heater door adjustment didn't fix it, I would be suspicious of a faulty or low-temp thermostat.

ALWAYS start at the top of the engine when searching for oil leaks. Rear of valve cover gasket is common. Oil filter adapter housing where it meets the block is another common leak area along with a leaking oil pressure sending unit. Rear main seal is less common but gets blamed often since the other places I mentioned above- The oil from them drips off the rear main seal area since it's the lowest part of your engine.

Just get this: http://www.eautoworks.com/Putco-H4--900 ... D7540.aspx And do this: Cruiser’s Headlight Upgrade Harness Instructions Absolutely plug and play. Remove grille and headlamp bulbs. I fed my harnesses from the passenger side starting between the battery and the back of the headlamp housing, over to the driver side. Plug the driver side bulb into the new harness. Attach the new harness's ground wire under one of the small bolts on the radiator support after scraping the paint off under it. Attach the harness to the existing harness behind the grille working toward the passenger side. . Plug the new harness plug into passenger headlamp. Plug original headlamp plug into receptacle on new harness. Attach the ground for the passenger side just like you did the driver side under a radiator support bolt. Attach relays with provided bracket on the passenger side inner fender. Connect power wires to battery. Your stock headlamps will be about 30% brighter as a result. Installs in less than half an hour. Prevents your headlight switch and it's associated wiring and plug from melting down as they are known to do with stock headlamps. Only increases that risk by adding more powerful lamps without upgrading the harness. You will not be disappointed. I guarantee it.

Hornbrod is correct. The ground refreshing will not only benefit the starting of your Jeep, but it affects all the grounds for your fuel injection system. Read the write-up. It details what sensor grounds are affected. This should be done to every Renix Jeep at least once in it's lifetime or under your ownership.. The C101 connector refreshing write-up I included in the other post is super critical, too. It's the junction of the super-highway of communication between the eCU and most all of the sensors. Poor connections equals poor info to and from the ECM.

Do the ground refreshing/mods and it will be even better.

I've never noticed that it had any "wiggle room" anyway. None of mine ever leaked.

Do this first: Renix Ground Refreshing The Renix era XJs and MJs were built with an under-engineered grounding system for the engine/transmission electronics. One problem in particular involves the multiple ground connection at the engine dipstick tube stud. A poor ground here can cause a multitude of driveabililty issues, wasted time, and wasted money replacing unnecessary components. The components grounding at the dipstick tube stud are: Distributor Sync Sensor, TCU main ground, TCU “Shift Point Logic”, Ignition control Module, Injectors, ECU main ground which other engine sensors ground through, Oxygen sensor, Knock Sensor, Cruise Control, and Transmission Sync signal. All extremely important stuff. The factory was aware of the issues with this ground point and addressed it by suggesting the following: Remove the nut holding the wire terminals to the stud. Verify that the stud is indeed tightened securely into the block. Scrape any and all paint from the stud’s mounting surface where the wires will attach. Must be clean, shiny and free of any oil, grease, or paint. Inspect the wire terminals. Check to see that none of the terminals are crimped over wire insulation instead of bare wire. Be sure the crimps are tight. It wouldn’t hurt to re-crimp them just as a matter of course. Sand and polish the wire terminals until clean and shiny on both sides. Reinstall all the wires to the stud and tighten the nut down securely. While you’re in that general area, locate the battery negative cable which is fastened to the engine block just forward of the dipstick stud. Remove the bolt, scrape the block to bare metal, clean and polish the cable terminal, and reattach securely. Another area where the grounding system on Renix era Jeeps was lacking is the engine to chassis ground. There is a braided cable from the back of the cylinder head that also attaches to the driver’s side of the firewall. This cable is undersized for it’s intended use and subject to corrosion and poor connections at each end. First off, remove the cable end from the firewall using a 15mm wrench or socket. Scrape the paint off down to bare metal and clean the wire terminal. Reattach securely. Remove the other end of the cable from the rear of the head using a 3’4” socket. Clean all the oil, paint and crud from the stud. Clean the wire terminal of the cable and reattach securely. A suggestion regarding the braided cable: I prefer to add a #4 Gauge cable from the firewall to a bolt on the rear of the intake manifold, either to a heat shield bolt or fuel rail bolt. A cable about 18” long with a 3/8” lug on each end works great and you can get one at any parts store already made up. Napa has them as part number 781116. A further improvement to the grounding system can be made using a #4 cable, about 10” long with 3/8” terminals at each end. Attach one end of this cable to the negative battery bolt and the other end under the closest 10mm headed bolt on the radiator support just forward of the battery. Napa part number 781115. If you want to upgrade your grounds and battery cables in general, contact Jon at www.kelleyswip.com. He makes an incredible cable upgrade for a very reasonable price. Revised 11-28-2011 Then do this: Renix Jeep C101 Connector Refreshing The C101 connector on 1987 and 1988 Renix Jeeps was a source of electrical resistance when the vehicles were new. So much so that the factory eliminated this connector in the 1989 and 1990 models. The factory recommended cleaning this connector to insure the proper voltage and ground signals between the ECU and the fuel injection sensors. We can only imagine how this connector has become a larger source of voltage loss and increased resistance over a period of almost 25 years. The C101 connector needs to be cleaned at least once in the lifetime of your vehicle. Chances are it’s never been done before. Almost every critical signal between the engine sensors, injectors, and the ECU travel the path through the C101. The C101 is located on the driver’s side firewall above and behind the brake booster. It is held together with a single bolt in it’s center. To get the connectors apart, simply remove the bolt and pull the halves apart. You will find the connector is packed with a black tar like substance which has hardened over time. Take a pocket screwdriver or the like and scrape out all the tar crap you can. Follow up by spraying out both connector halves with brake cleaner and then swabbing out the remainder of the tar. Repeat this procedure until the tar is totally removed. This may require 3 or more repetitions. Wipe out the connectors after spraying with a soft cloth. If you have a small pick or dental tool tweak the female connectors on the one side so they grab the pins on the opposite side a bit tighter. Apply a true dielectric grease, not the stuff that came with your brake pads, to the connection and bolt it back together. Revised 11-29-2011

Al, what year is your Comanche? Does it crank for a long time before it starts or does it crank slow due to the low tempereature?

Starting in the start position and dying when the key goes to the on positon is typical of a faulty fuel pump ballast resistor located near the air cleaner on the driver side inner fender. It's a ceramic white deal about 3/4" by 3" with a wire at each end. To test it, just hook the wires togither bypassing the resistor.

Check an early intake/exhaust gasket against a later model gasket and see if there are any differences.

I've done more than 3 without it and had no issues.

242 is great for what you're needing.

Airtex pump?

Plan for the worst and hope for the best. There are too many variables to answer that question definitively. Kinda like answering the question "How long is a piece of string?"

Forgot I wrote this. It addresses the poor instrument panel ground. Improving the Instrument Panel Ground 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, Seatbelt and key warning, trans 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 have a 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. **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.** Revised 11-29-2011

Do that, but don't forget the ground points on the driver's side inner fender.

87 to 88 Cherokee or Comanche.

30 psi I have found this to be the best all-around pressure on both of my Jeeps, one with 235s and the other with 31s. IIRC, that's the factory recommended pressure.

Is your heater blend air door opening all the way? Look under the passenger side dash and move the COLD to HEAT control lever back and forth. When moved to HEAT, does the lever hit the stop? If not, adjust the cable clip right there.

This has nothing to do with the coolant reservoir. Just eliminate the heater control valve.

Put a new 195* thermostat in it.

A good throttle body cleaning along with the Idle Air Controller in the tB would be a good place to start. If that doesn't cure it, I'd be checking the TPS

83502545 is the Chrysler part number. Napa has them, too.