Eagle

Castrol Syntec 5W30 in winter, 10W40 in summer.

Morons. If they were going to round off 2.7 to 3, why not round off 5.4 to 5 ... or 6? It's not like those gauges are finely calibrated, precision instruments.

I expected that the Canadian gauge would be in kPa -- that's what the FSM uses. Numbers are numbers, they are more precise than "halfway." That said, if max is 5.4 then straight up (the mid-point) should be 2.7. The U.S. gauge has a range of 0 to 80 psi, and the mid-point is 40. The quarter point is 20 and 3/4 is 60, with tick marks at the tens. The scale is linear, not exponential. The FSM spec for oil pressure (for the 4.0L) is 13 psi (89.6 kPa) minimum (warm) at idle RPM, and 37 to 75 psi (255 to 517 kPa) above 1600 RPM. 80 psi is 552 kPa. 75 psi is 517 kPa, so the FSM is just doing a direct conversion. 40 psi is 276 kPa. To convert kPa to bars, just divide by 100.

Pretty sure he uses a FAST fuel injection system in his MJ drag truck, not Renix. Check it out. :thumbsup: If he does, he has changed it. I know Bob personally and I did a bit of work on the truck and the engine while he was building it. It was pure Renix when he first completed it and started racing it.

What weight oil is in the engine, and how cold does it get at night where you live? It might be helpful if you give us the actual numbers instead of reading the oil pressure like a gas gauge.

Agreed. Bob Salemi is running one in an NHRA pro stock Comanche in Rhode Island. Basically it just needs bigger injectors for a stroker.

On V8s I always liked the 4-barrel because you had small primary venturis for economy, and larger secondaries for when you needed more airflow and performance. I vaguely remember seeing AFBs as small as 400 CFM, and I always thought that might be a good carb for a 4.0L. Does anyone make a 2-barrel that has a primary and a secondary, rather than two primary holes that are the same size and no secondary?

Chrysler also used to (and maybe still does) sell through the Mopar Performance Catalog an MPFI conversion for the 258 engines. It was basically the Chrysler HO system used on the 1995 Wrangler 4.0L, packaged as a stand-alone conversion. Hesco also sold one -- which might have been the same system. None of them are inexpensive. Mopar: http://www.mopar.com/assets/pdf/performance/catalog/19561_JeepPerformanceCatalog_v02.pdf It'll lighten your wallet by about three grand.

If the votage drop still happens with the blower on high speed, the resistor pack isn't causing it because there is no resistor in the circuit on high speed. I would pull your blower motor and check it out physically. When you get it out, there's a round "squirrel cage" blower impeller on the end that goes into the air box. Try spinning it by hand. It should spin freely, with no resistance (or almost no resistance). What you've got is a mechanical device with a metal shaft that rotates in two metal bushings (not bearings) that haven't been lubricated in25 years. It may be running dry at this point, and metal on metal doesn't work very well. It may be possible to dribbly some lightweight oil into the end with the impeller on it. The other end is sealed, but people have carefully drilled a small hole in the little bump where the end of the shaft is located so they can get a few drops of oil in there. Then cover the hole with tape or mastic or RTV. Just don't use too much oil, because you don't want it to seep into the electrical contacts inside.

I've been at this for well over 50 years and this is the first time I've ever heard of a switch to control air shock ride height.

The engine starts with all the bypasses, so of course you can get it running. Just be patient and don't break things while trying to fix it. How did your father "unhook" the ignition switch, and how did you bypass the fuel pump? You may have bypassed some important connections. First, are you aware that the key cylinder in the steering column is NOT the ignition switch? The actual switch is the thingie (technical term) shown in Hornbrod's post. It's at the bottom of the steering column, and the key tumbler connects to it by an operating rod. If that rod is out of adjustment, the switch may or may not function. IMHO you should either take your key cylinder to a locksmith and get new keys made for it, or just buy a replacement cylinder (it's a GM Saginaw steering column, so if you can't find one listed for AMC/Jeep, just buy one for a Chevy). Then check the ballast resister, as shown in Fernando's post. You could also check to verify that the fuel pump has a good ground, although being in Texas I wouldn't think rust and corrosion would be a big issue. One step at a time, and keep us posted on how it's going.

If you want to sell it, take it to the classifieds.

Not just a different mount -- a different bumper. That's not a factory Jeep Comanche bumper.

I agree that it's better to begin with a known good block and do your own build. When I was younger and doing my own engines, I sent the bare blocks and heads to a local shop to be steam cleaned, oil passages cleaned out, bored (if necessary) and honed, and new cam bearings installed. They also checked the head for flatness and trued it up if necessary. Then I brought the block and heads home and did the assembly myself. You'll need a piston ring compressor, and a package of plastigage for checking the bearing clearance. If you don't feel like lapping the valves in yourself, don't strip the head before taking it to the shop -- let the shop do the valve job. But every procedure you can do for yourself keeps $$$ in your pocket. Just remember that a 4.0L is long and heavy engine. You'll need an engine stand. Don't skimp -- buy a good one.

Unless things have changed, they're pretty much universal in fit. The difference is in the strength of the spring.

Quick test -- the heater blower uses resistors to control the lower speeds, but there is no resistor on the high speed setting. Try running your heater on the high setting and watch the volt meter. See if it makes any difference.

That's correct in theory. If you have about 4 gallons in a 16-gallon tank (a quarter of a tank, in other words), I would adjust it to read a little bit lower than 1/4. I prefer to have a bit of a cushion over what the tank is telling me.

I think I'm using a 13-pound cap on mine.

The heater blower uses resistors to control the speed, and resistors create draw in the electrical system. It's also possible that your blower motor itself is getting tired and drawing more current than a new one would. That said, I suspect that your alternator is dying. The parts chains like Auto Zone and Advance Auto can bench test it for you if you take it in. A regular shop can probably test it in the vehicle, but they'll charge. The chain stores will test it free, but you have to carry it in.

Can't hurt. But the line itself is still rubber -- it just has a stainless braid around it for reinforcement. Heat will still kill a stainless line. You need to make certain it's routed well clear of the exhaust manifold, and if you're going to do much dune riding you might consider wrapping it with a foil insulation of some type.

Butt weld? You don't use a flanging tool?

Too close to the exhaust manifold. Sand dunes ==> engine works hard, manifolds get very hot, slow speed, no air circulation to cool the line.

You don't need Photoshop. It's probably easier in Photoshop, if you know how to use it (which I don't), but I did my shortened version using good old Microsoft Paint (the version that was bundled with Windows XP)

Here's what the red one might look like with a shorter box:

I found this: Looks like the bed is a long bed? That makes it too long, IMHO. My late wife was from Chile. All over South America, 4-door pickups are very popular, in the small pickup lines. We rented one once for a ten-day trip around the lakes region of Chile, a few hundred miles south of Santiago. They're not "beautiful" by any stretch of the imagination, but they're also not insanely ugly, and they're not so long that you need a CDL to drive them. The box is typically about a 5-foot box -- even shorter than an MJ shortbed. Not great for hauling huge loads, but most people never use a box to capacity anyway. Another one: And then I found this: