1987Comanche

This is an annoying thing that's developed in the past few months. I transplanted the full gauge cluster into the '90 from my '87 2 yrs ago when I bought the '90 and sold the '87. Originally the cluster started life in a jy XJ but everything works fine. it's a mechanical speedo. The commute to work is about 20 miles one way. I'll leave, drive to work, and everything is fine. About once a week I'll leave work, look down, and find the needle is stuck at at the bottom of the scale (5 mph) on the cluster. Tapping the lens a few times gets it moving again. I'm typically at 20-25mph and it jumps right up to that speed and works fine. What's interesting is that it doesn't do it at any other time, i.e. running errands, leaving the house, etc. Ideas?

The double sided Chrysler key lock will fit. A friend and I pulled a set of '93 XJ door and hatch locks from a donor with keys and put all 3 locks into his '90 XJ with the AMC/GM style locks. The locks fit fine but you need the actuator rods too. We didn't know this and ended up bending some welding rod to fashion a new actuator rod.

I hit the Black Fri 1/2 off sale at LKQ too! Only difference was that my local LKQ is in Greenville, SC. The XJs were pretty picked over (no MJs) but I grabbed a ton of GM pass car stuff (sensors, coil packs, interior parts, etc). Spent $200 so it would actually have been $400. It was a good day :)

Do you have lights/gauges, etc when you turn the key to run or is it completely dead? When you turn the key to start do you see the gauges move and/or lights dim? You may have to pull the starter and have it bench tested at Advance, Auto Zone, etc. If that doesn't lead anywhere try bumping the engine over with a breaker bar. It's possible the motor is locked up. If none of the above then yes, you're back at a bad ignition switch or deeper electrical problem.

This is grasping at straws but it seems like that's about all you have left at this point. Could you have a short in the harness that's messing with the ECU? Based on what you've said about your noid light/injector tests it sounds like one of your quad drivers (internal to the ECU) is burned up. Perhaps something in the harness is shorting them out. I saw an odd one like this once in an '88 Grand AM 2.5 TBI. The engine would run for 10 min then die, owner tried to figure it out, ended up setting the throttle body on fire and really screwed it up. 1st mechanic replaced parts piecemeal and couldn't make it run. I hit the JY and picked up ECU, complete throttle body, Coil packs and module, and CPS and got it to run. Apparently the throttle body shorted out and blew the ECU. The new ECU fried the moment mechanic #1 turned the key. This, in turn, fried something in the new throttle body. It was a mess!

The TSB has the ECU #s listed but, as a quick and dirty method, look for the MOPAR tag indicating it's a reman ecu.

Does it not want to idle when it's cold? The fuel mapping in the OE Renix ECU was flawed and Chrysler/Mopar issued an updated ECU that had the correct tables. I had to 2 foot my '90 4.0 out of the development every morning until I was lucky enough to stumble upon the updated ECU at the boneyard. I would never have guessed this without finding the TSB. Have him look up TSB 18-54-89 Revision A.

The standing bid from the crusher/recycler was $150 for anything with a frame and $200 for anything with an engine. He won a good majority of the cars by default.

This morning there was a Corvette Salvage auction with 100+ cars. Since it was less than 1 hr from the house I decided to go. I didn't buy anything but it was well worth the $10 in gas to go kick some tires. I took a ton of pics...thought y'all would like to see what was there. Top bid on any car was $1500

Some digital clusters have a memory chip that contains the mileage. Perhaps you can swap it from cluster to cluster?

Easy upgrade. If I remember correctly the smallest alternator was a 4.75" case and the larger one was the 5.25" case (68A and 125A perhaps??). My truck was A/C delete and sans HD cooling package so it came with the smallest alternator they had. Not only was the larger one an upgrade, it was cheaper too!! :clapping: The hardest part about the upgrade was arguing with the genius at the parts store. He insisted he couldn't sell me the larger one. The only change to the truck was using a pry bar to open up the mounting ear on the bracket bolted to the engine. I had to pry it 3/8" or so farther apart to fit the new alternator in.

A Gearwrench on the end of the Torx bit works great. Buy the Sears Torx bit, loosen the set screw, and remove the Torx bit from the chrome socket (holder). Now you have Torx on one end and hex on the other.

My '87 was never inspected in NC :clapping: . I moved to this state, registered it, and had the 1 yr "grace" period to get it inspected. The well thought out inspection/registration system was supposed to block registration if I didn't have a current inspection. I tried it and the renewal went right through so I never bothered getting it inspected. If there are no stickers and a valid registration constitutes proof of inspection then it must have been inspected, right? On the flip side they gave me a devil of a time with the '90. It had been in NC it's entire life and hadn't moved in a year or so when I got it. I couldn't register it without having a valid inspection and I couldn't get it inspected without a valid registration. :???:

I have the old bench seat from my MJ in the basement and you can have it if you want it. It's gray vinyl and in ok shape. Don't know if you ever travel to WNC but I'm not far off I-26.

Look behind the driver's side headlight. You should see a red wire at one end of the connector with no mating wire (I think female end is missing). Probe for 12V with the foglight switch on and you'll find it has power.

Yes. The Frams are cheaply constructed and use cardboard end caps on the filtration media. The Champ E-core filters (Wally World, AC Delco, et al) are cheaply constructed as well, using a plastic matrix for the filtration media. Purolator classics have a steel body throughout and are closest to the pre E-core AC Delcos.

I found my towing mirrors to be annoying, took them off, and replaced them with (non spring) conventional mirrors. I couldn't comfortably put my arm out the window and yes, they did vibrate around some at speed. If you want the OE MJ towing mirrors & brackets I think I still have them in the basement. Shoot me a PM.

The bell shaped one works and the more conventional (requires oil press sending unit socket to remove/install) works as well. I've been sold both for my '90.

She moved to a new home almost 2 yrs ago. I sold the '87 4cyl AX-5 2WD with 19XXXX miles to buy the '90 I-6 AX-15 4WD with 117,000 miles. I pulled the VC on the '87 to replace the lifters and pushrods and drove her for 1.5 yrs with no leaks. I used to have an extra 2.5 OE VC laying around here somewhere. Do you want me to look for it? A 1/16" gasket would not have sealed mine either.

The VC/Head mating surface on my 2.5 was as cast! It apparently missed the milling operation entirely. Imagine my surprise at prying the leaky old cover off and finding that :nuts:

The VC on my '87 was like that. I used RTV instead of a gasket, which will fill in the imperfections. Not pretty but it worked ok.

Found this on Craigslist. Haven't been to the yard yet but it would be a waste to let good '91 parts go... http://asheville.craigslist.org/pts/2564973379.html If anyone heads up there let me know what the yard is like :clapping:

Factory floors were 18 ga steel. 16 ga is a good replacement though you'll have a harder time forming the corners/bends. Typically any 1018 cold rolled steel (CRS) will work just fine. Most steel supply houses will let you pick through the cutoffs and purchase by weight. 16 ga CRS for the floors of my '87 was $10. No galvanized if you're welding though...

I took some photos of Renix vs HO side by side before I sold the HO one I picked up at the jy. viewtopic.php?f=2&t=29716&hilit=renix+ho+sending+unit

The MT2500 is a solid tool but it's been superceded by the Solus and a few others. I hooked up our old MT2500 up to my '87 2.5 for giggles just to see what it could read. The answer is not a whole heck of a lot. More than anything you need the DRB connectors for whatever scanner you have. I know they made them for the MT2500 and I would think they made them for the newer tools as well. Everything I saw on the OSD you could have measured with a multimeter and/or translated into a reading with the FSM at your side. The Renix computers simply don't provide the amount of a data that you can get from a GM 12 pin ALDL or any OBD II system.