Eagle

Before you buy a new tank ... be sure the tank is the problem. I replaced the tank in my '87 SWB a couple of years ago. Drove to the gas station, filled up the tank, and saw gasoline streaming out from under the truck. The problem wasn't the tank at all. Where the hard gas lines go into the fuel pump mounting flange apparently is a vulnerable spot. The lines vibrate or something, and develop a hairline crack where they go through the flange. That's where the leak is often found.

Headlights 6014 Brake and front turn signal lights 1157 (the front should be 1157NA) Backup lights 1156.

That's not the issue. Read some of the other threads discussing this. The issue is that the auxiliary fan in the Renix years is controlled by a switch that mounts in the driver's side radiator tank. The '99 radiator will not have a bung for the switch to thread into, and the switch is MUCH too large to screw into the t-stat housing. Which means you will have to find an alternate way of controlling the auxiliary fan. It seems like most of the free world has decided that converting from the closed to the open cooling system is a "must do" project, yet they ignore the fact that it provides exactly zero additional cooling capability and creates problems that still have not been 100% resolved. IMHO it's a waste of time and effort.

90 was the last year for the mechanical speedo. He has a 91 -- he needs an electronic speedo.

Yeah. Start by learning the correct terminology for the year vehicle. I don't mean to be rude -- I'm trying to point out you're going to confuse yourself, and everyone you ask about this problem. The 90 Jeep 4.0L engine (as well as the 2.5L, in fact) is what is referred to as a Renix system. "Renix" is short for Renault-Bendix, because those two companies collaborated on the design of the system back when Renault had a major stake in AMC-Jeep. Your '90 is the last year of the Renix ignition/injection system. You do not have a PCM. You do not have an ECM. You have a crankshaft position sensor (which is universally referred to as the CPS), a camshaft position sensor (which is what you are referring to as the trigger wheel in the distributor, but unlike an older transistor ignition system this one doesn't generate the spark, it only tells the engine if each cylinder is on a compression stroke or an exhaust stroke), an ignition control module, and an ECU (Engine Control Unit). The ignition module does perform some functions, and if it goes bad (which is rare) it will result in no spark. ECU failure is very rare, but possible. By far the most prevalent cause of no starts, bad running/skips, and intermittent no starts is the CPS -- the crankshaft position sensor. Or the wiring for it -- the wire runs VERY close to the manifold, and if not properly routed can easily have the insulation burned off and short out on the manifold.

What year Jeep and what tranny? You have to be VERY careful what you use in the Jeep 5-speeds. The AX-15s (and probably also the AX-5s, although I have never seen anyone write about them) do NOT like any gear oil that has sulpher in it. The recommended factory stuff is only rated GL-3, because the higher ratings have more sulpher. The sulpher attacks the bronze in the synchronizers, and pretty soon you don't have synchronizers. If this stuff is the same as the fairly new (3+ years?) Pennzoil Synchromesh gear lube, I called Pennzoil when it first came out and asked them if it's good for Jeep trannies. They said it is formulated for the NVG3550 and 4500 trannies, and that it should NOT be used in the AX-15 or the BA 10/5. However, they declined to tell me just why, or to tell me what the formulation is. If I remember correctly, it carries no GL- rating whatsoever. I have three bottles of it on the shelf in the garage, but I don't dare use it.

5-1/4"

2-1/4" assuming you are asking about a 4.0L. It's 2-1/2" into the catalytic converter, and the connector from the cat to the muffler exits the cat as 2-1/2" then necks down to 2-1/4"

Look closer at your 87, 88 and 89. If they have an electric fan, the fan sensor is in the driver's side radiator tank, about halfway down. The temp sensor in the side of the block is for data input to the ECU and has nothing to do with the aux. fan.

His donor vehicle was an XJ. He found that the XJ chassis harness didn't mate up with the MJ chassis harness and he had to make a number of custom connections, as well as trace some circuits.

Those 10-spoke "turbine" rims are 15x7. They're good for 10.50" inch wide tires. The usual rule of thumb is that tire width should not exceed rim width + 4". However, as you get into very large tires, with lots of sidewall height to allow for transitions, you can go wider. However, do NOT run tires wider than 10.50 on those rims on an MJ. Even 10.50s will rub the lower control arms (in fact, even 30x9.50s will rub the lower control arms), but a worse problem is how close the sidewalls on the rear will be to the springs and the inner fenders. Running 31x10.50s on those rims, I had black rubber marks all over the inner wheel wells in the abck after every trip, and there's just a tiny bit of clearance to the leaf springs. An 11.50" tire will be another half inch closer to the fender, and will be probably making contact with the rear leaf springs. If you need tires wider than 10.50 you're better off using aftermarket rims with less backspacing.

I knew a guy in NAXJA who did a 2.5L to 4.0L conversion, including all the wiring, in a 72-hour marathon. That was working by himself, for 72 hours straight. I would figure if you haven't done one before you should plan on about twice that number of hours, and preferably not straight through.

Pull the wire off and see where the needle goes. Then ground the wire directly to the block and see where the needle goes. I can never remember which is which -- one should zero the gauge, the other should peg it beyond 80. If that works, the gauge is okay. If the connecter looks good, then replace the sending unit.

Randy, are you referring to the cam position sensor in the distributor? I would check that, too. I would also check the wiring leading to the ignition module to see if you're getting any flow in. If there's no 12-volts arriving at the coil/ignition module, then there's nothing for the coil to bump up to 70,000 volts or whatever the coil sends to the plugs.

My wife had one. Not bad. It ain't a Jeep but it isn't bad. Rode decent, drove okay. I don't recall what year hers was. It was the last year thay they had a low range transfer case. The next year it got slightly longer and heavier, and they eliminated the low range. I lost interest in it as a budget alternative to a Cherokee after that.

Take the oil filter AND the mount off the block. You probably need new o-rings in there anyway, so it's a good excuse to do the job.

The 242 is not AWD -- it still offers a 2WD selection. It also offers 4-Hi with differential (AWD), 4-Hi locked (same as the 231 Part-time), and 4-Lo locked (same as the 231 low range). It's a great tranny for a multi-purpose vehicle that sees street use in slippery weather but also gets used off-road on occasion. The Hummer version is stronger, and I have seen conflicting information as to whether or not you can swap in some Hummer parts to beef up the Jeep 242.

They do screw in, and I'm 90% certain they are an SAE thread. I believe the manifold end is a coarse thread and the "working" end is a fine thread, but I may be recalling the way the old AMC engines were set up.

What RPMs do you turn at 65 MPH, about 1200? I think if you get better than about 12 MPG it's a modern miracle.

Even the short wheelbase Commanche has a longer wheelbase than the Cherokee. I don't think an XJ tailpipe will work in any MJ.

Nope. Actually, they coincide at -40

Or lack of coordination, or something like that. I didn't know Pete was heading off to meet Mickey, and I promised my wife I'd take her on a sightseeing trip this weekend. (In a freakin' blizzard, naturally.) We'll be leaving Friday morning and won't be back until Sunday evening, and I won't have access to the Internet while we're away. Which means all of you boys and girls are on your own for the weekend, so be sure you behave yourselves or Pete will have to give you time out when he gets back. If you find any spam or such, send me a PM and I'll "launder" it when I get back.

A chronic problem with the older XJs and MJs is that the gauges become inaccurate. I think it's due to a poor ground between the gauge cluster and the dashboard/chassis. In my '88 XJ, ALL the gauges read low. My voltmeter shows barely out of the red, yet if I check with a V.O.M. at the battery with the engine running, I'm right where I should be. Temp gauge runs at the first tick between the COLD and 210 marks, yet I have good heat. Oil pressure reads 40 psi on the highway running 5W50 Castrol Syntec. And when I fill the tank to the point of spilling out the filler neck, the gauge only reads 7/8 full. Except on very cold, damp mornings ... when everything reads normal until the engine gets up to operating temperature, then the gauges gradually slide down to being wrong. Moral -- do not use the factory gauges for diagnostics. Just know where they usually run, and pay attention when they read different from normal.

That is very true for "short" (half-length) AALs, and very much less true for full-length AALs. However, very few "full-length" AALs are really full length. For example, the Rancho "full-length" AAL is almost full-length for an XJ, but MJ springs are 5" longer than XJ springs, so it obviously isn't full-length under an MJ. But it also isn't trying to massively over-power the original spring pack and create a monster lift with one leaf, so it works pretty will. The ideal AAL (for a moderate lift) is the main leaves of another set of MJ springs, with the eyes cut off. The arch matches, and they are a true full length. MJ spring packs are hard to find, but older S-10 and early Dakota packs are similar in length and easy to find in junk yards. Once the weather warms up, I'm looking at putting an XJ main leaf into an MJ pack, with the goal of increasing the spring rate (carrying capacity) without gaining much lift. should be interesting.

If you read and understood the fine print about PayPal, you would never use PayPal. They can reach right into YOUR bank account and take money out. All it takes is for a buyer to claim you didn't advertise something accurately, or didn't ship the item(s). Thanks, but no thanks. I won't use them for a variety of reasons. If I were to have a moment of temporary insanity and sign up, the first thing I would do is open a separate account at a bank I have never done any business with, put the bare minimum $50 or $100 in the account, and use that for the PayPal account.