Eagle

Why are you adding a relay? The aux fan already has a relay -- just add a wire from your dash switch to the input side of the relay control circuit.

You have bypassed the ballast resistor, I assume, by just jumpering the two wires at the resistor location on the inner fender, right? But the START circuit still has its bypass that directs full 12 volts to the fuel pump when the engine is cranking on the starter motor. That bypasses the whole ballast resistor portion of the circuit, so I would suspect a break somewhere in that START bypass circuit.

No, the Chief had manual windows, bench seat and mini console. You could get power windows as an option, but they weren't part of the package. I don't know if buckets and a full console were even optional in the Chief. Most all the goodies were included in the Eliminator package.

Switch to 15W50 full synthetic.

The highway pressure is a bit low, but if the idle pressure doesn't go below 25 psi you're good. The factory spec is 13 psi minimum at idle, and 37 to 75 psi above 1600 RPM. And that's for a NEW engine.

'86 didn't have a clutch safety interlock. '88 didn't, and I'm pretty certain m9 '89 doesn't. I think that first appeared in the mid- to late 90s. Your CPS may be failing. That can cause hard starting. (Before it causes no starting.)

Any chance you replaced the water pump and got one for a 4.2L engine by mistake? The 4.2L used conventional vee belts and the water pump rotates the opposite direction -- but the housing bolt pattern is the same so it WILL bolt right onto a 4.0L engine. With the impeller blades pitched the wrong way, it can't create much flow.

Not at 1700 (or 1900) RPM. An internal combustion engine is, fundamentally, an air pump. Flow mods don't make any significant difference in the lower part of the RPM band. You benefit from flow improvements at high RPM, where the stock system can't flow enough to produce the power needed. For a race engine it's important. For a daily driver, it's not important. At 1900 RPM, a 4.0L engine is moving an absolute maximum of 133 CFM through the engine ... and that's assuming 100 percent volumetric exchange on every cylinder, which an internal combustion engine never achieves. The real key is ... what's your shift point? 3600 RPM? So you need to flow 266 CFM if you're shifting at 3600 RPM -- which is probably high if you're running an RV (torque) cam.

If you will be welding on "new" perches, there's no need to cut the old ones off.

No, Pat, I did not miss the part about the intake and the cam. I also did not miss where you said it will be primarily a daily driver. Lowering the torque curve does not result in a need for a high flow exhaust system ... and especially not for an engine that's not being run most of the time up at or near the red line. FWIW, the choice of cam has no effect on the engine speed/road speed relationship -- that's a mechanical ration that is entirely determined by tire diameter, axle ratio, and transmission ratio. If you are running 235/75-15 tires through 3.07 gears, then I respectfully submit that if your tach is telling you 1700 RPM at 70 MPH, your tachometer is wrong. Those numbers I toss out are all calculated based on actual tire manufacturers' data, in most cases actual revolutions-per-mile ... which is the only accurate way to calculate the engine speed from the road speed. A different tire model or make may vary by a few RPMs, but not by 200. Nonetheless ... Gibson's Jeep exhausts are tuned for hauling and they are reputed to really work. I never tried one but I dated a gal who had a Gibson system in her TJ. If I were ever to go for an aftermarket system, that's what I'd get.

235s and 3.07 gears does not make for a combination that calls for a high flow exhaust. Back when my '88 XJ was fairly new, the first time the exhaust went my brother was managing a Speedy muffler shop. He talked me into letting him install a Speedy (Walker, I think) 2-1/2" cat back system with a 2-1/2" turbo muffler. I will admit it sounded great. Not much louder than the OEM exhaust, but a bit deeper and throatier. Problem was, I hated it from the day it was installed. It's the only time in my life that I counted the days until an exhaust system rusted out so I could justify replacing it. I LOST toque -- I could feel it didn't have as much power when accelerating, and (more important to me) I also lost about 2 MPG in fuel economy. When that system finally needed to be replaced, I went to Auto Zone for a stock 2-1/4" exhaust and an OEM-type 2-1/4" muffler. The torque was back, the gas mileage came back to where it had been pre-turbo, and life was (generally) good. With 235 tires running through 3.07 gearing, your 70 MPH highway cruise will be just over 1900 RPM. Skip 5th gear and run in 4th and it's still only 2580 RPM. I don't think the high flow is going to do for you what you think it is, or what you want. If you MUST go high flow, I'd suggest Gibson. Their exhausrs are tuned for torque-type cams and power bands. And they sound GREAT behind the Jeep 4.0 engine -- the only performance aftermarket exhaust that (IMHO) doesn't sound like crap.

The actual switch is on the base of the steering column. Follow the wires from the firewall.

How do you drive and what's the gearing? Basically, unless you're doing drag racing or road racing, I think a stock replacement is all you need. Buy it once from Auto Zone and it's guaranteed for life. The thing with wanting a high flow is ... do you need it? The 4.0L engine is redlined at 5,000 RPM, and you probably can't get much beyond that even if you tried because the valve trail will float and act like a rev limiter. But a daily driver is probably going to spend the majority of it's life under 3,000 RPM, and probably under 2,500 RPM. You just don't NEED the extra capacity of a high flow muffler to do that.

One person didn't stop that. JCR was selling a bumper that was not suitable for the purpose for which they were implying it was made. If they hadn't stopped making it, someone would have sued them under the implied warranty of merchantability provisions of the Uniform Commercial Code and they would have been a lot less happy. Why they didn't just make it using the correct material for the draw tube is a mystery, but I'm very happy I didn't get suckered into buying one.

De acuerdo, amigo.

I don't want it, but I do think the bed is interesting, and I might be tempted to fabricate something like that for an MJ if I had one with a trashed bed. Except that my bodyworking skills are limited to unbolting an old door or fender and bolting on a new one ...

MJs are one size larger than XJs. IIRC, the XJ uses 5/16" and the MJ uses 3/8".

Disagree. Most all XJ/MJ replacement radiators are now truly universal - fit all. Coolant ports for the AW4 are there, the bung hole for the Renix aux fan sensor is there in the left tank, as well as the HO fill port. Just make sure before you buy. Some aftermarket rads are indeed "universal" -- with both the radiator/fill cap and the temp sensor bung. One of the most popular is the GDI, and the last time I bought one it did NOT have the bung. We know because the radiator shop didn't understand the significance when I ordered one for a 1988 Cherokee so he just ordered the same one he usually orders, and most of what he had been seeing was the new style. It had a radiator cap but no sensor bung, so we had to send it back.

Fix what? What's broken?

No, that's not all you have to do. If you have air conditioning, the auxiliary electric fan is controlled by a sensor that mounts in the left hand (driver's side) tank of the radiator. Because the auxiliary fan is controlled by the ECU on the 1991 and newer systems, most of the "open" style radiators don't have a bung into which to install the sensor. So then you're faced with trying to figure out how you're going to get the aux fan to turn on when needed. There have been a LOT of different ways proposed over the years. Most of them didn't work.

The "old" radiator and the "new" radiator are exactly the same size and both operate at the same (or nearly the same) pressure. I am constantly mystified by the number of people who seem to think changing to the new style ("open") cooling system is in any way an up-grade.

If it shifts when the engine isn't running but won't shift when the engine is running, the clutch is NOT working. It's a clutch problem, not a transmission problem.

Yes I am, I will be using a set of aftermarket guages for temp, oil pressure and Amperage but I am curious now as to whether the other guages will drop in to the cluster and just work. The fuel gauge changed both polarity and resistance range from the Renix cluster to the late-model cluster. The other gauges did not change, IIRC. But there is no ammeter -- the MJ used a voltmeter. There's nothing to change there -- volts are volts, there is no sender.

Why would you want to disconnect the factory voltmeter?

Nope.