1987Comanche

There are some differences but nothing really meaningful...it's the amount of filtering media based on the size of the filter. If you're asking can you use the '96 oil filter (with adapter) on the '89 the answer is yes. I put a '96 XJ adapter on my '90 MJ. The filter is a bit harder to change but the PF-13 is a lot easier to get and the truck rattles less on cold starts (horizontal mount vs vertical mount).

I'm at the tail end of reassembling the interior on my '90 MJ and the small center console (for use with bench seat) is shot. It's cracked/broken in 4 different places and rather than JB welding it back together I'd like to find something else. I used JY XJ carpet in the interior so the cutout for the late 80s/early 90s center console is there. I didn't grab the console because I didn't think it would look good cut down to fit in the bench seat interior. What else would be a good donor? Early ZJ?

Does it have V belts or Serpentine? My '87 used a PH3387A/PF47 filter and had V belts. I'm assuming the engine was from an '86 because, from what I can tell, they sent to a Serpentine belt in '87

It was a bad TPS on my '90

I installed the OE fan and all OE wiring to support it last night and it works well. I'll have to wait until the truck gets hot to see if the radiator temp switch works (jumpered it last night to see if my wiring worked and it did). It took me forever to figure out how to install it but only took 1 hr 45 minutes to actually put in.

Find a metal supply place and look through their leftovers. Anything that isn't a full sheet will be sold by the pound. I spent $12 for 16 gauge metal to fix the floors in my old '87.

I changed the VC in December and both hoses were clear as I had to swap them both (went from AL VC to stamped steel). I haven't touched the top end since. The inside of the engine was definitely carboned up. When I pulled the VC I spent 2 hrs scraping crud from the top of the cyl head. I probably had a 12oz Coke can full of carbon when I was done. The oil pan and timing cover were pretty bad too. When I replaced the RMS again a few weeks ago I found another 10-12 little chunks of carbon in the oil pan. From what I can tell the truck went about 7K miles in the last 3 years they had it. Perhaps stuck rings that finally freed themselves?? I've been running an AC Delco PF13 since bringing her home.

Here's the story. I picked up my '90 MJ 4.0L about 6 months ago from the PO (who was also the original owner). The miles were pretty low (117K) and he parked it because of electrical problems. I dragged this gem home and have been driving her to work and back since (about 50 hwy miles per day...I'm up to 121,600 now). Until about 2 weeks ago I'd find a light brown puddle every day at work where the oil was spitting into the airbox and leaking out the drain hole in the bottom. I put a VC from a '96 4.0 a few months ago and that helped some but I still had a decent amount of blowby. I did as much as I could, shrugged my shoulders and said the heck with it. About 2 weeks ago I noticed that this particular puddle was no longer forming (I still have other oil puddles but no tell tale light brown one from the airbox). Any ideas why the blowby would cease to be a problem?

I dug around and couldn't find anything I needed. It looks like the A/C harness and non A/C harness were different. I know that a fog light front harness is different than a standard front harness though they both clip into the same connector behind the driver's headlight. I stripped the (&*)( out of the JY XJ looking for something like that and chased it all the way back to the fusible link. I had wiring fanned out all over the engine compartment. No clips or plug-ins anywhere along the way :(

I found an available feed from the fuel pump relay which will only provide voltage when the f/p is running. If my truck had A/C it would be used to run the A/C relay. Seems perfect for my fan relay. Thoughts?

I'm going to add the OE cooling fan to my '90 4L AX-15 (no A/C) and I spent part of yesterday stripping down a wiring harness at the jy. I pulled the relay, temp switch, fan connector, diode, fusible link power feed, conduit, and all associated wiring. My donor was an '89 4.0 AW4 with factory A/C. The ignition on power feed from the '89 was orange/blk tracer that plugged into the front harness (single connector and the ignition on feed is yellow in the harness). It was located by the ignition module and starter solenoid on the pass side. For some reason I can't find the orange/blk single connector in my truck at all. I did find a 2 prong connector (one red wire, one black so it should be constant power & ground) tucked under the relay cover near the fender. It has about 2' of wire coiled so I assume it's for an option the truck never came with. Anyone know what this one is? Assuming the ignition on plug-in feed doesn't exist on my truck where is the best place to tap into the ignition on power feed? Ignition module?

There's wiring present for 2 horns: low tone and high tone. One on Driver's side & one on pass side. The base trucks had a single tone horn on the driver's side. A horn on the pass side indicates you have dual tone.

I've purchased 2 new ones off e-bay so far (JP5B if I remember correctly): one for my old '87 and one for the '90. They both worked ok and were around $95 shipped to my door.

E-bay. I picked up a new rad for $67 and converted my '90 4.0L to an open system. Mine leaked at the rad and the old pressure bottle so the conversion was a no brainer for me. No change in temp,operation, or anything else except lack of leakage :)

Crank position sensor. It's only a $30 part new but it's a pain to reach. If you look at the bell housing from the driver's side you should be able to see it. I tried the resistance test on mine and it passed but it still had an internal problem. Replacing it seems to have taken care of my no start issue.

Have you replaced the CPS in the bellhousing? My '90 went through a few no starting fits and this appears to have been the problem.

Windshield wiper and turn signal control. The mating connector would be on the steering column.

For the pump & pickup tube assembly: put the pickup tube in the freezer for an hour or so and put the pump in the oven at 250 or 275 for 10-15 minutes. Lock a pair of Vise-Grips on the tube just ahead of the stop (bump on the pickup tube) and hammer on the Vise-Grips. It should go together with a few hits. No sealant needed.

I did the lifters and pushrods on my '87 2.5L in 1/2 a day. You need a lifter removal tool which is about $12 at Advance Auto. Lifters were $5/ea and pushrods were $2/ea. Also pick up a tube of slick assy lube. I thought it was fairly easy...required some patience but pretty straightforward. You can always go back and replace the valve stem seals later on. Just a general question: Why did AMC allow one to pull the lifters on the 2.5 without pulling the head but not the 4.0?

I ran into the exact same problem with my '90. I finally said &(* it and started working screwdrivers in between the pan and block on the front pass side (spot with best access/leverage). After about 2 hrs and finally deciding I was going to destroy the pan I got it to break free. I ended up peeling the mating surface back about 3" and distorted the front 1/4 of the pan before I heard the popping sound of the seal breaking free. I was ultimately able to use the body hammer & dolly set to flatten it back out but, if another pan was available I would have given up on the first one. And BTW the RMS is still leaking...I have to go back in again at some point.

Clutch master or clutch slave. What does the firewall near the fuse panel look like? Rusty? Paint missing? Fuse block melted at all? If so then definitely the master. Either way the master would be the 1st thing I'd replace. You can't get to the internal slave without pulling the trans.

Exactly what I needed to know. :thumbsup: I suspected they were the same but wanted to be sure before I dropped the tank.

I'd vote fuel delivery problem since it idles ok but bogs down when you give it gas. FP regulator, injector, and/or TPS. You have plenty of air and, from your list of tune up parts, spark as well. What do the wires leading to the injector look like? Any chance of a high def video??

Are the fuel tank rollover valves/vent valves interchangeable between the XJ and MJ (specifically 1990)? I discovered my tank is holding a lot of pressure and apparently neither vent valve works. I pulled a set of vent valves from a '90 XJ that work fine (vacuum tested both) and they look like they'll fit. I know the tanks & sending units are different so before I drop the tank again I wanted to confirm they would, in fact, be a direct replacement.

You'll find the 2.5 fuel injector to be crazy expensive new. I have a spare 2.5 TBI unit that I kept for parts when I had my '87. If you want anything from it send me a PM.