1987Comanche

I'd probably go for a new high vol oil pump. They are a known weak link on these engines. True it's $$ but it will correct a deficiency.

They are a plug-n-play install though. I added them to both the '87 and the '90. Grab the bracket, light, and pigtail from a like year vehicle and you're all set.

Theoretically it's there to dampen the engine vibration as the 2.5 is a rough running little beast with no balance shafts. The 4.0 is a better balanced engine and doesn't need it. Not sure what would happen if you ran without one though. :dunno:

I have a good used spare on my shelf. PM me if you're interested and we can work on a price, etc.

If all else fails purchase a Fram Sure Drain (ebay, etc) and put in place of the drain plug. As long as you can cram it in the thing will never have to be unscrewed again. I'm not a big fan of Fram but that works pretty well. I've had it on 2 trucks with boogered up oil pan threads.

Thanks for the good info. I'll check it out in the next few days.

This started yesterday (or at some point since I last had the headlights/running lights on). When you pull the headlight switch to either running lights or headlights the cluster, etc lights up but the right turn signal indicator in the cluster comes on as well. I don't see any bulbs out and the flasher pulses both left and right turn signals ok. My first thought was a bad bulb but both front and rear signals seem ok as viewed from outside the truck. Ideas?

Cherokee rollover valves and grommets are identical and XJs are plentiful at the JY.

Disconnect your electric cooling fan and go for a ride on the highway. If it comes on at speed (50mph+) it may be blocking air trying to go across the rad.

Bad Idle Speed Controller.

Fold the soft portion of the splash guards out of the way (behind headlights, by the horn) and look at the bumper bracket to body mount. 3 15 MM on each side and it will drop right off the truck.

I was cleaning out the basement today and I came across my spare 2.5L TBI unit. I pulled everything that might be worthwhile (injector, TPS, etc) and noticed that the TPS looks identical to the 4.0 TPS. I looked up parts at Auto Zone online and they list a different TPS for each app even though they look identical. Are they different in output, etc or are they same sensor?

http://knoxville.craigslist.org/cto/1810180472.html

LKQ price list: http://www.lkqselfserve.com/FindaLocati ... fault.aspx

My full gauge cluster was $25 at LKQ U pull it. $75 for a bumper isn't too bad... my front bumper came off a '90 Cherokee Country (all grey, including end caps) with fog lights for $60. LKQ would have been the same to slightly more b/c they nickel and dime you for everything (bumper, each bracket, each fog light, etc). I'd say that's a good price for a rear bumper as I've never actually seen a decent one at the jy.

You no longer have to look at the index in the Electrical Manual b/c you know the book like the back of your hand.

The connection in the standard wheel didn't work well on either the '87 or the '90. Also the horn itself was corroded in the '87 and worked intermittently. The sport wheel (3 spoke) didn't work that well until I got the metal plate (contactor?) in exactly the right place. Now it's fine. I had no problems finding extra sport wheel parts at the jy.

That plug was left by the factory for dealer installed A/C. I used one of the pins to provide key on 12V+ for my fan relay (not load, just trigger). This way the fan won't come on if the truck is shut off. Sure. It might be best to PM me and take it offline. Perhaps you can document rewiring the relay and put in the how to section. You can give me honorable mention :)

That's definitely not OE. A diode should not be spliced inline with the red power lead as it serves no purpose there. That's the power feed for the relay and it's fed by the fusible link from the junction block/solenoid behind the battery. Did you trace the orange wire back? The diode should be on it. Yes, this will work for the time being. Hit the JY and cut the connector off a temp switch. Then you can wire a switch to that pigtail that can be easily removed.

The small orange diode is the only one I've ever seen...perhaps yours has been replaced once already? :dunno: The '87 and '90 manuals only call out one diode, though they don't elaborate on what it looks like. I will say that if the diode has a removable connector it should be listed in the FSM. My '87 electrical manual has a call out and sketch of every connector in the truck (which is why I kept it for the '90). Theoretically any 12V diode with 2 inputs and 1 output should work. It doesn't carry any current, just triggers the relay.

If I remember correctly you need to check voltage on the legs of the diode. Apply +12V to the line running from the compressor. You should see +12V at the relay and nothing at the temp switch. Now apply +12V to the temp switch. You should see +12V at the relay and none at the compressor (sounds like you did b/c the fan came on). If you see anything other than this the diode is bad. What causes them to fail? Old age, too much dirt, etc.

Not sure about a new one but I probably have 1 or 2 extras floating around. It took me 3 tries at the jy to get everything I needed to add the cooling fan. Be warned you have to physically cut the old one out of the harness. If I can find one of the old ones you're welcome to it as long as you pay shipping (prob $2-3 as it's pretty small). Send me a PM if you want me to dig for it. Did you jump the coolant temp switch to see if the fan works?

Bad Zener diode in the wiring (small orange thing buried in there). I wired in the aux cooling fan a few months ago. If you want to figure out whether the fan works unplug the temp switch in the radiator and jump the pins in the harness. It should come right on.

Told you the alignment dowel was the way to go! Glad you got it out!

I used a steel Craftsman alignment dowel, hammer, and lots of careful alignment and holding my breath prior to each hit. I originally tried tapping but ultimately had to hit the old RMS pretty hard 3 or 4X to get it moving. I didn't loosen any of the other bearing caps when I was pulling the seal.