Jeep Creep: Off-Road Tech and Maintenance

In your Jeep Creep questions, please list your first and last names, your hometown, and your state/province/country, so that we can publish that information here. If you don’t provide this information, we may not be able to publish your question and answer. Don’t forget to be as complete as possible with the description of your Jeep and its problems, too. Send your questions to editor@off-road.com, Attn: Jeep Creep.

Previous Jeep Creep ColumnsDecember 2012

November 2012

October 2012
No Jeep recalls this month.

Foggy Lights
I can’t figure out how to clear up my Jeep’s headlights. I have an ’07 Jeep Sahara and I live outside of Tucson on a dirt road that I have to drive twice a day for work. We also get a lot of wind here, which is why I think my headlights have gone foggy and hazy. I checked with the Jeep dealer and found out they can be replaced but cost a lot. I picked some little spots down low on the lens and tried rubbing compound and wax, but the wax didn’t work and the rubbing compound made it worse. Can you help me?
Larry Sutton
Tucson, AZ
You must be unlucky, Larry. I live in Arizona as well and drive a 2007 Rubicon Unlimited and haven’t had a problem with fogged-over headlight lenses, yet. But I’ve seen other Jeeps with the same problem, and I think I have a solution. I’d seen ads on television for products that solve this dilemma so I stopped by a local O’Reilly Auto Parts and found JK Mothers Powerball for Lights, which the label said was a headlight restoration kit for yellowed and clouded headlights. There were other products on the shelf as well but Mothers’ products have a really good reputation. Contributor Jaime Hernandez wrote a piece on restoring your vehicle’s headlights with Meguiar’s PlastX. View that story here: http://www.off-road.com/trucks-4x4/tech/restoring-your-offroad-vehicles-cloudy-headlights-52100.html.

Converting a FlattyI got lucky last year and found a 1947 CJ2 while on vacation in New Mexico. It was stock and in pretty good shape and actually ran, so I hooked it up behind my motorhome (it had a tow bar and I bought a set of magnetic towing lights) and brought it home. I’ve tried using the Jeep on Southern California trails with its flat-head four banger and three-speed manual transmission and it is fun but slow, and it gets stuck easily. And its brakes are tiny! I didn’t measure them, but I think the brakes are about 8 inches by 1 inch and any kind of a creek crossing makes them useless. I want to put a V8—probably a Chevy, since they are so common—in it but can’t make up my mind what transmission to use. I know it probably means a huge answer, but could you give me a hint on what I have to do?
Jerry Zaspell
Garden Grove, CA
Wow, Jerry! I don’t know whether to be envious or thankful it’s not my project. And I don’t think we have the space here that’s needed to tell you everything you’ll need to know—that would take a book, not a portion of a monthly column. Back in the day—sixties and seventies—when I dropped a Chevy 265 V8 into my ’46 CJ2, all the parts you’ll need would be readily available. Let’s start with the brakes: Rather than trying to find a kit for larger brakes, I’d suggest you buy a set of more modern axles that you can have cut down to fit your CJ’s width (you’ll be able to find replacement brake parts much easier). Rather than keeping the OEM Willys three-speed—as I did—plan on using an automatic (if you’re going with a Chevy engine, pick either a TH350 or TH400) transmission and either adapt it to your T-case or spend the money for an Advance Adapters’ Atlas transfer case. And for the engine, since you mentioned your preference for a Chevy, I suggest either a 350 or a 4.3L V6. The 350 will give you more power; the V6 will give you more power than you have now and better fuel mileage. Since you live in California, you may have to smog the engine according to its age (so make sure you get an engine with EFI and all the computer system components) or due to the age of your Jeep you may not have to—that’s between you and the DMV. You may also have to cut up the firewall to accommodate the Chevy’s distributor and I believe Flex Seal (a product I’ve seen on TV) will work for resealing the firewall. It’s also supposed to be good for sealing gas tanks, oil pans, and floor pans. This is just a rough outline of what you’ll need—as I said earlier, you’ll need a book for all the information—so contact Advance Adapters at www.advanceadapters.com. They do offer the books needed for this conversion. And best of luck to you. I hope to see you and the finished project on the trail one of these days, Jerry.
Fouled-up 4-banger
I have purchased a 1989 Wrangler with the 2.5L four-cylinder. Someone changed the original carburetor to a 2-bbl carb. with an adapter to the TBI intake manifold. I purchased a Rochester Monojet and an ‘84 intake manifold and installed them. The Jeep now runs fine but under load it retards or something and runs like crap. All the distributor wires are not connected; there are three of them. I also purchased an ‘84 distributor but it looks the same as what I got. The wiring has been all chopped up, but I have an isolator block and a coil. I tried wiring direct but same result. Is this possibly a weak or intermittent spark? Timing is bouncing around. Is the computer somehow still connected to the motor? Does the module in the distributor now need power or a controller? Aloha.
Punakev Woodworth
Hilo, HI
Wow, you have too many problems listed to diagnose from afar. If you’re a decent mechanic, buy a good shop manual with all the wiring diagrams and vacuum lines shown. If not, take it to a good shop that knows Jeep engines.

Goofy GaugesI have a 2000 Wrangler 4.0L. Recently my gauges started acting funky; voltmeter would peg over 19 volts then all the gauges would quit, also the radio would quit, then it would come back on and the voltmeter would peg again. I hooked it up to a computer and got a P0622 “Generator field not switching properly” error code. I have replaced the alternator and ignition switch; still the same. Also, even when my volt gauge says 19 volts, the actual output from the alternator is correct (15.5V). Could the PCU be bad?
Joe Z
Taylor, MI
Joe, you need to trace down your bad ground to your dashboard. You may want to run a new one from the battery to the dash’s connection to avoid it going bad again. Once you correct the grounding problem, you can address the PCU if you need to at that time.

Full-Time CherokeeI was told that the AW4 automatic transmission from later model XJs could not be used in my 1996 due to computer changes or something or other that was changed in ‘97 and later models. Is this true? What year AW4s can be used as direct replacements in the ‘96 Cherokee XJ?
Jerry Dudley
Yoder, CO
Stick to the 1996, Jerry. They’re unique.

Missing Four LiterMy name is Steve Devine and I live in New Zealand. I have a 1996 4.0L Grand Cherokee Laredo auto. I love having an interesting, unique truck, but it has given me a lot of problems! The specific problem at present I have is an annoying miss in the motor, but just at low revs/top gear, i.e. moving slowly from lights. There is no miss once I accelerate. Everything I do changes the dynamics of the miss (such as amount, when it happens, etc.), but doesn’t fix it. I have cleaned the plugs, then replaced them. I have cleaned the distributor/rotor, then replaced. I have been swapping leads one at time, but nothing changes. Any other suggestions?
Steve Devine
New Zealand
Yepper, Steve, I have a few suggestions. Check all the vacuum lines for a leak. You may also have a bad fuel injector head, and lastly it could be a bad plug wire.

No Go In FourI have an ‘83 Wagoneer. The 4x4 is not currently working because of the vacuum system. I was wondering if there is a fix or bypass to this? Can I just use some Warn Manual locking hubs? Posi-Lok says they don’t work for a Wagoneer but I am wondering if I can do that instead.
Jason Cummins
I suggest you order a transfer case rebuild kit (www.fourwheelparts.com or www.quadratec.com) and go through the transfer case completely. At the same time ask if free-wheeling hubs are available for your model Wagoneer.

Lurching CherokeeI just purchased a ‘99 Cherokee Sport, 4.0L, standard transmission, with 120k miles. After taking it on a road trip I noticed some trouble. After a couple hours of driving at 75 mph the engine would sporadically lurch. It seemed to get progressively worse, but after stopping for an hour or so it was fine until another two hours of driving at high speed when it started again. The same thing happened the next day driving back home.
It never stalled but seemed like it would if I had run it long enough. Also, it seemed to lurch more when I was giving it some gas (like when I started to go up a hill). The “check engine” light came on during one of the lurches, then went off overnight, and came back again the next day with another lurch. To further add to my confusion, I got off the interstate during a time when the engine was lurching and as I coasted to a stop I noticed my engine was running near 3,000 rpm in neutral. I tried lifting the gas pedal off the floor, but that wasn’t the issue. Within a minute or so it came back down.
Incidentally, my cruise control doesn’t hold a solid speed, and my blower will switch from the upper vents to the defrost vents depending on what speed I'm traveling. It seems like under load the vents switch to defrost, and then back again when I’ve let up on the gas. Also, with the blower off, when I give it a lot of gas to get up a hill there seems to be some air coming in the defrost vent, while at normal speeds there is none.
Mike
You may have more than one problem, Mike. You could have a sticky idle air control, bad spark plugs and/or a bad coil pack. In addition to these possible conditions, you may also have vacuum line problems under the dash (which would cause the switching of the air flow).
As usual, each month, I’m shouting out a huge THANK YOU to Paul Schupp at Rock Lizard 4x4 in Kingman, Arizona, for his invaluable assistance in answering many of the Jeep Creep questions.