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I need a new MAT sensor for my 88 Comanche 2.5 TBI. Chrysler p/n 3300 2382, not available? I have check all the part stores, no luck. I can find one for the YJ but it does not have the 8" harness. Any ideas?

I was reviewing the 2.5L CEC System document located at jeepgarage.free.fr/own/2.5l, my 88 Comanche has an entirely different system than they show in the vacuum diagram. They also talk about a "knock sensor" located on the cylinder head? Their document is for a Cherokee, I can't imagine that the systems would be that different but maybe so.

I want to follow this thread, my 2.5 has a simular problem. My engine starts and runs good when cold but will have a intermittent slow idle when warm. If that engine dies when I'm going around a corner, that's scarey, it takes an incredible amount of force to turn the wheel! I need to read up on how to measure and adjust my TPS switch.

It looks like that leak is taken care of, I will keep an eye on it. Now I have a new leak, the 6" water pipe that angles up out of the maniflod. Looks like I will have to remove the throttle body assembly to get that one out. This is just one thing after another. I wanted a little project to work on, now I have it...

I pulled the stud out and sure enough it threads through into the water jacket. I put some "Honda Bond HT" on the stud and threaded it back in and appears to be working OK, no leak, time will tell... I have been looking at this silicone called Honda Bond HT, this is some impressive stuff. A very high temp silicone 600+ that resists oil. I did a small unqualified design of experiments and compaired it to the high temp Permatex Ultra black, it may be a better sealant. I will have to try it on a few differnt applications to make a better judgment. The only trouble with the Honda Bond HT is the price $$, what is a good seal worth?

My rebuillt 2.5 long block has developed a water leak on the front threaded stud of the # 1 exhaust port? Is this threaded into a water jacket? What would be a good way to seal the stud?

I now have about 600 miles on the engine and it is really starting to smooth out! I'm amazed at the change the engine is going through. My first tank of gas gave me 23.87 MPG.

I don't think the engine was actually broken in, they did some pressure testing and a short spin up for compression check. There is some special testing on high-end motors where they will actually run them on a dyno, I doubt my $1400 2.5 AMC saw any of that testing. Here is a clip on the factory testing from their web site. I'm using the old fashion dino juice, I have heard that synthetic oil is not a good break-in oil on the old technology engines. Chevron Supreme, API service SM.

I'm not running any special break-in oil, just 5w-30 and a Mobil1 oil filter. I got the engine from AutoZone, Proformance is the builder in Springfield, Mo. They look like a pretty good operation, lots of ISO certifications and process controls. They are a teir 1 engine supplier to Chrysler for remanufactured engines. One thing I need to understand is the EGR valve circuit. What triggers the solenoid to open and close the EGR valve? I'm not sure if mine is working properly, when I apply a vacuum source to the valve there is no change in the engine RPM?

I pulled the vacuum line on the EGR and noticed there is no vacuum present in the idle condition, should there be? Good point on the O2 sensor, I have noticed the idle searching up and down a bit. I put a timing light on the engine and saw the timing @ 10 degrees, that is really not adjustable. At this altitude a little extra timing is probably OK and lower vacuum is normal. There are only 42 miles on the engine now, it will take a while for things to settle out and break-in.

88 Comanche, 2.5, 4spd, no A/C Been working on getting the new motor installed. It seems to run real good until the engine warms up. It starts and idles fine when cold, shows about 16 in.Hg vacuum with a steady needle. As the engine warms up, about 3 minutes, the vacuum will drop to 10-8 in.Hg. and bounce like a blurr. The engine seems to drive fine but if you lift off the gas when coming to a stop the engine will stall. You can start it and it will idle fine unless you punch the throttle off and on.

I'm not home right now so I can't check for sure but 3/8-16 comes to mind for the bolts. There is a stud on the front exhaust #1 that is a different size. Ace hardware carries the good grade 8 bolts. It is important to use the factory conical washers. They are designed to absorb the varied expansion and contraction of the dissimular metals, aluminum and cast iron.

The heavy red wire goes back through a fuse link to the silver relay where the battery is connected. There are a group of 4 ring terminals that share the post on the relay. I will use it to run my hood light.

My hood drop light has a two pin connector, but it came from a newer Cherokee?

Starting to put the engine bay back together and have one red wire ~ 10-12ga. single spade connetor and a blue vacuum line. Where do these go? See photo. This is and 88, 2.5, 4spd, no A/C[http][imghttp][/img][/img]

My 88 MJ has matching white fender flares. How can I remove the paint and what color will the base material be? I want them to be semi-flat back.

Is there adjustment on the ignition timing on a 2.5 TBI? The casting of the ditributor has a saddle the locates to the clamping screw. That tells me if it is not inserted to the perfect position the timing will be off? I can see 0 to 20 degrees marked on the timing cover. You could be off one tooth when you insert the distributor, then where is your timing going to be? The manual tells you to be sure the oil pump is in the 3:00 o'clock position before inserting the distributor, does that set the timing?

I have a 88 w/2.5. Trying to install new hoses between the heater core and the heater control valve, these hoses are about 3" long. The heater core outlets are .750 & .625, the inlet on the control valves are both .625. There is a special p/n for the for the reducing hose 52003887, Jeep says it has been discontinued. Has anybody woked this issue before? I'm thinking I maybe able to sleeve the .625 outlet up to .750, not sure what I would use.

I can see where the ports need a bit of trimming, I would certinaly clean that up. My thought on the foil side woud be to put that against the cylinder head. To help eliminate the galvanic response between dissimular metals you wouldn't want that steel bridging between aluminum and cast iron? But it would be hard to argue with Fel-Pro.

I have a Fel-Pro intake/exhaust gasket that has a perferated metal side and a paper side. This gasket is symetrical and can mount either way, I don't see any markings for orientation? Any ideas?

There are two alignment bushing/sleeves in the back of the engine block that align the bell-housing to the block. I went to remove one with a pair of pliers and it just crumbled, now what do I do? How important are these? Where might a person find a replacement?

I was looking at the slave cylinder on my 88 AX4 and noticed some plastic locking clips where you can compress the slave cylinder and lock it in that position? Is that for new build shipping or is there some special procedure for installation? Both the clutch and slave cylinder look brand new so they are going back in.

Most clutch disks are marked "flywheel" for proper installation., the one I have is not. Which way does the clutch disk go? On the splined portion of the center disk there is a flush side and one side of the splines protrudes about .500". Which side goes to the flywheel? The factory service manual shows a picture with the protruding splines toward the flywheel, but there is not reference to direction.

That is right , no A/C. I'm still trying to decide if I should rebuild the 2.5 or do the 4.0 upgrade? If I was to find a Cherokee to use for the upgrade what would be the prefered year? I'm thinking ~95-96. A premium rebuild on that 2.5 will cost me about $1800, I can find a decent 4.0 Cherokee for about $3500. Not sure if my drive-shafts will work with the 4.0 upgrade?

I'm in the process of pulling the engine and disconnecting all the wires, I found one that was not plugged to anything. It is bundled in the harness that runs from the battery terminal to the started motor. It is orange with a single push type socket. The photo shows it lying across the alternator bracket. Any ideas? [http]