Interstate Trouble

I wonder if you might have a stuck injector and when the engine is working hard like that the oil is getting diluted. That would explain the gassy smell, the low oil pressure, and the louder piston slap. I had that happen in a VW years ago (I know).

You might also have a sensor (temp sensor?) that is bad and confusing the computer into making the engine run really rich.

Jeff DeWitt

Dave Jost wrote:

Bill, the street tires are long gone.

Jeff, would it explain low oil pressure only when idling? How do I check it? The sensor I need a computer to check, but I'd like to avoid taking it to the Jeep shop. The guys there will tell me that I need Mopar parts by the crate load.

Thanks, D

What was your engine rpm at, say sixty? I am thinking that 3.07 gears and

31 inch tires might be too much for even fourth gear. If so, then regearing would fix a lot. Street tires would help too, if you want to run it on the street.

Earle

Dave,

I'm not sure about the oil pressure. It might be that you have a good tight engine and even with the oil thinned out the upper pressure is still being limited by the oil pressure relief valve, but when the engine is idling the pump isn't spinning nearly as fast and the pressure is far more dependent on the viscosity of the oil.

I haven't tried this on a Jeep but if you can remove the injectors from the cylinder head but still have the fuel and electrical connected switch the ignition on so the fuel system pressurizes and then check the injectors. They should all be tight and dry. Any that have fuel coming out of them are bad.

Some of the guys in the newsgroup must be real experts on these systems and can tell you for sure if I know what I'm talking about, as I said I haven't had to do this on a Jeep.

300,000 miles and no problems with the fuel system, exhaust, AC, heater, suspension, transmission, universal joints...

Jeff DeWitt

Dave Jost wrote:

I don't think that's it. I ran 31's on my TJ with 3.07s and while 5th gear was only for downhills, and there was alot of clutch slipping to launch, it was nothing like he's describing. My milage improved 1-2 mpg when I went to 4.10.

The OP was getting 6mpg - can't blame that on the tires.

I get the best gas mileage keeping mine at 2300 to 2500 rpm.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

RoyJ wrote:

I did some searching and came across an older string titled something like "YJ excessive... mystery sensor." It seemed to be going down the same alley I am.

My question, can anyone describe to me how to check those sensors. Like I said earlier I like to avoid my dealership like the plague.. I just need a sensor primer per say.

Also I think a regear is mandatory. I've been searching for a cheap 8.8 that I could regear with the front at the same time, and then slide under, perhaps it is time to increase the search. Any help on that would also be great.

Thanks, D

I have 3.31's and 33's and very seldom use 1st low. 2nd for starting with 3rd low for running usually.

I also forget about 5th and get about 23 mpg.

Mike

RoyJ wrote:

You have something seriously crapped out from the sounds of it.

I would start by opening the distributor cap and seeing what the posts and rotor looked like.

Then I would be opening the air filter to see if it is plugged. If blocked with oily dirt, suspect plugged rear CCV tube or grommet hole.

Next I would be pulling the plugs to look for a really clean or dirty one.

If clean suspect too much gas or a bad injector, if really dirty, suspect electrical.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

Dave Jost wrote:

...

Pull the dipstick... smell the oil.. smell like gas? Bad. Fix raw fuel problem, change oil.

Put fuel pressure gauge on fuel rail... start engine... stop engine. Fuel pressure go down? Bad. Fix injector. __ Steve .