Jeep Creep: Off-Road Jeep Questions Answers

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 Jeep questions to

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May 2013

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No Jeep recalls this month.

Grand Sputtering
I am trying to fix my ‘95 V-8 Grand Cherokee. The car sputters at higher RPM, even when it is in neutral. This happens all the time. I also had a problem where the RPM were fluctuating drastically (from 200 to 2,000 RPM) even when the pedal position was held in a constant position. That problem seems intermittent. I replaced the fuel filter and fuel pump and it has not helped. Any other suggestions?
Max

Max, you need to do one of two things. The Grand’s computer will have stored codes, which will tell you exactly what is going on. Take it to a good tune-up shop and have the codes taken care of and corrected, or buy a computer module from AEV, 4-Wheel Parts, Summit Racing, etc., and correct the codes yourself. The module—once you use it—will only work on that specific vehicle.

Low Air Volume
I have a 2000 Grand Cherokee Limited. It has dual-zoned temperature control. The passenger side only blows at half the volume as the driver side. Does this model have a cabin air filter that might be dirty, or could it be something not opening up all the way?
Neil Chief
Belleville, IL

The Grand Cherokee uses vacuum lines and vacuum modules to control the routing of the heater/air conditioner’s air flow, Neil. I think one of the lines might be crimped or a module has gone bad. You’ll need to buy a repair manual that includes diagrams of all the vacuum lines and the locations of the vacuum modules. This will lead you to the problem.

Lost Bolts
I have a 1997 Jeep Grand Cherokee with 114,000 miles on it. I just had the transmission rebuilt but the torque converter shield was lost in the process. I’ve since found the shield but not the bolts. What size bolts do I need to install the shield?
Cathy Polisher
Canton, NC

Let your fingers do the walking, Cathy, and find a local pick-your-part recycling yard (a junk yard where you do your own work finding the parts you need). Find a matching Cherokee and remove all the bolts you need. However, you should return to the repair shop and have it replace the shield bolts you need.

Cam Sensor
Hey, my husband and I are debating on whether to take my ‘99 Jeep Cherokee to the mechanic, or put in the new camshaft position sensor himself. This all depends on where it’s located. I was hoping you could help us with that. I had Advanced Auto Parts hook their code reader up to it when my check engine light came on. The code read: camshaft position sensor A Bank 1.
Emily

It’s in the distributor, Emily, but in my opinion, you should have a mechanic install the new sensor. There may be other work needed that your husband couldn’t do.

Another Sad Sensor
I have a 1991 Wrangler. I changed the five-speed out this morning. I got in a hurry and forgot to unhook the crankshaft positioning sensor. The wires broke off even with the sensor. I put the other five-speed in and figured the other sensor would be the same. I think the other five-speed came out of a Cherokee, possibly an ‘88 or ‘89. The plug on that sensor is a flat three-prong and with only two wires on it. The plug on my ‘91 had a round plug with three wires. Is there any way to make the two-wire sensor work? If so, how do I wire it?
Matt

Sorry, Matt, but you’ll have to pull the transmission again, install the correct sensor, and connect it up properly.

More Sensor Sadness
I have installed a 5.2L V8 into my CJ with great success. I have moved to the speedometer adapter issue. In an article I read, a pass-through VSS is identified. I have acquired one of these, but it has only two wires where the donor harness has three. Can the two-wire sensor be used in place of the three-wire sensor? If so, which wires go where?
Marty Bowyer
Reno, NV

No, Marty, you need the proper sensor. Call the new 4-Wheel Parts store out in Sparks (775-386-2100), and they’ll put you on the right track.

Great ‘78
I’ve got a ‘78 CJ 5 that for its age is in great shape. I would like to begin restoring the Jeep and want to start with the exhaust system. There are a couple of things going on that I’d like to fix. First, the Jeep does not like to start when it’s cold. I have to pump the gas pedal, try and crank it, and then let it sit for several minutes before it will fire up. Would replacing the carburetor fix this or do you think it’s something more? Also, when it’s running it emits heavy fumes that are sometimes difficult to bear. My thought is that in addition to the carburetor I will need to replace the headers and possibly the entire exhaust system? Any thoughts on how I should get this project started are greatly appreciated?
Kyle

Kyle, your problem is not with the exhaust system—unless it’s leaking. Your problem is with the Jeep’s fuel delivery system; it’s running too rich. This is what is causing the fumes and the hard starting. Instead of “treading water” with a replacement carburetor, switch to the Howell electronic fuel injection system. It’ll be far better off-road, more fuel efficient, and affected far less by altitude.

Liberty Boot
My wife’s 2003 Jeep Liberty Renegade was in the shop and we were told that the driveshaft’s boot was missing (don’t know how that happened). They replaced the whole driveshaft. They said that’s how the part comes. You can’t just replace the boot. Is that correct?
Bruce

Bad news, Bruce, that’s correct. That’s the way a Liberty’s driveshaft comes from the factory.

I’m Exhausted
I have the head and the MPI 4.2L Head Conversion kit. I bought the OEM exhaust manifold for a ‘95 Wrangler 4.0L engine. The face of the exhaust manifold is about 1/8-inch thicker than the intake and, therefore, I cannot bolt them up together. Looking for offset washers or shaving the face? Any ideas?
Bill Aliggan
Oceanside, CA

Bill, you’re sitting within a few minutes of several 4-Wheel Parts stores—Santa Ana, Temecula, San Marcos, etc.—call one of them for your offset washers. They should have the washers in stock.

Another 4.2L Head Conversion
I have found a ton of info/write-ups on swapping a 4.0L head on a 4.2L. However, I can find nothing on what to do with the EGR valve. I know not everyone who has done this is installing fuel injection. I want to use my existing intake with a Motorcraft 2100 carburetor. Emissions are not an issue, but I am concerned about detonation. Do I need to fabricate a pipe to connect the EGR or can I get away without it after installing the 4.0 HO head? All comments are welcome.
Eric Koederitz
Savannah, GA

You’ll have to fabricate a pipe, Eric. But I don’t understand not using electronic fuel injection. It’s far superior in all on-road and off-road conditions.

Bad Tranny
I have a ‘96 Grand Cherokee Laredo. Sometimes when I come to a stop the tranny locks up and stalls the engine. Also it started being very slow going into gear when it’s cold. Do you have any ideas what might be causing this?
Will Fish
Calgary, Alberta

Sorry to have to tell you this, Will, but your transmission has gone south for the winter. You’ll have to rebuild it.

Fuel Be Gone
One morning, about two weeks ago, I tried starting my Jeep. I unlocked it with my remote, turned the key and the first thing that I saw was that my fuel gauge did not respond and that the empty warning light came on. This was very strange as I had just filled it up the day before. I tried turning the ignition and the engine cranked over but did not start. Can you help me?
Tony Diesel
Cape Town, South Africa

First thing to check, Tony, is to look under the Jeep for a large puddle of fuel. If there is no puddle, see if someone stole your fuel. Disconnect the fuel line from the fuel injection and try cranking the engine. Fuel should flow from the line. If none flows, reconnect the fuel line at the EFI and disconnect it from the gas tank’s outlet. Again crank the engine—I’m assuming you have EFI since your Jeep is new enough to have an electronic remote—the in-tank fuel pump should pump fuel out. If not, I’d say someone stole your fuel. If you have out-flowing fuel at the tank but not at the engine, you have an obstruction in the fuel line (crimp, clog, or clogged fuel filter). If you had fuel at the engine, then you have other electronic problems that will have to be solved on-site (take it to a good tune-up shop).

Slipping Laredo
I have a 2001 Jeep Cherokee Laredo that seems to slip sometimes. When this happens, the check engine light comes on and the car runs funny. The code is P0320. When I erase the code the car runs fine. This happens about once a month. Could you help me?
Vincent Hammer
Elizabeth, NJ

“P0320” indicates a No Crank Reference Signal at the PCM (crankshaft position sensor), which means a reference signal at the crankshaft position sensor is not detected during engine cranking. “P0320” could also mean No RPM Signal to PCM (crankshaft position sensor signal to JTEC). A CKP signal has not been detected at the PCM, which means the sensor has failed. However, there are two sensors involved; the cam position sensor and the crank position sensor, so you might have to replace both of them.

1. Cam position sensor, which is on the front of the engine—location varies depending on engine—and is most definitely not in the distributor. There is no distributor on those engines; they’re electronically controlled. The cam position sensor sits .30 inches from one of the camshafts.

2. Crank position sensor, which that code is referencing, is the one that failed. (They usually fail in pairs, though.) The crank position sensor is harder to get to. It’s on the back of the engine, near the transfer case, or in the distributor (depending on engine).

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.

Previous Jeep Creep Columns
May 2013

April 2013

March 2013