im1986

Ok hear goes, round 2.

I just bought a 1995 Jeep Grand Cherokee Orvis Edition, 5.2 V8, 170k, good running rig.

The ZJ sat since 2007, last week the owner had a motor put in with 65k on it (i have paperwork to prove it), and then i bought it. It runs great, starts right up and purrs like a kitten. However when you get to 2000 RPM, it all the sudden starts jolting around, stuttering, and running rough. If you let off the gas it goes away, and if you floor it it goes away. The previous owner thought maybe it was just the old gas in the tank? I am thinking maybe something else.

Anyway, if you guys have some thoughts, please let me know.

Thanks.

im1986

Today I replaced the fuel filter and still no change.

If anyone has any thoughts or suggestions I would like to hear them.

Thanks.

JeepsterXJ89

There is a TSB on spark plug wire routing that can cause a hesitation/miss on the mopar v8. you can check for burn marks on your coil/plug wires. mine was obvious. did the TSB and it is much better. might not be it, but it is very cheap to do and might fix your issue. Good luck!

im1986

Thanks. What is a TSB? I will chech for burn marks.

JeepsterXJ89

Technical Service Bulletin. Information from the factory on how to fix a common problem. The one I am talking about can be found at http://dodgeram.info/tsb/1998/18-48-98.htm

JeepsterXJ89

Also, look for burn marks where the wires cross or where any wire contacts metal.

im1986

Thanks. This is very helpful.

johnbanghart

sounds to me 2 wires are crossed i had this happen to me i did accel cap and rotor in and i mixxed up i think #4and8 cyclender i ran fine idle great then when i punched the gass it sputterd at like 2000 rpms, so i figured i had something backwards i went and downloaded the firing order printed it out and re went through all the wires sure enuff thats what it was
ps. mines is the 97 grand cherokee limited with the 318

im1986

So I ended up taking it into the shop to get it diagnosed. But i am not really understanding what they are telling me. Here is what the paperwork says.

"distributor is installed incorrectly, cylinder 1 is 3 terminals off, distributor must be pulled and installed correctly"

So I am trying to figure out what they mean by the word "terminals?" Are they saying the distributor is 3 degrees off? How do i go about setting the distributor timing on these 318's?

I paid for the diagnostics on the phone, and they left the paperwork in the front seat. they are now closed till monday morning, so i cant even call them to figure out what they are talking about.

Any help would be great.

thanks.

johnbanghart

sounds to me there telling you your timing is off or to far advanced, kinda like what i did but not really ahhah as i just had 2 wires backward lol, sound like what it is isnt really terrible and can be fixxed ps. i can give you a way to do timming, i havent done this in along time but we used to get a timing gun and flash the bottom ballancer while turning the distributor accordingly.

im1986

Well I talked to the mechanic who put the motor in the cherokee. I told him that my shop diagnosed the distributor was not installed correctly, and he told me that he knew that. He said that he could not figure out how to install it correctly, so he tried to trick the computer into thinking that everything was correct. He said it was running like it does now, but that the computer should learn the new distributor position and compensate for it. WHAT A LOAD OF B.S.

I was so mad on the phone, the jeep should never of left his shop without it running right. He said he would fix it for free, but his shop is over an hour away, and frankly i would never trust his work. If i cant get to it this weekend, I am just going to pay my shop on monday to get it done right. At least i know i can trust them.

Just so very frustrating.

im1986

Ok so Update.

I had the distributor installed correctly and timed. New cap and rotor. New plug wires. New plugs. New ignition coil. And the thing still sputters and backfires like crazy.

Does anyone have any more thoughts on what to look at?

Thanks.

88XJSteve

Maybe try the crank position sensor? Maybe its loose or bad?

I know my old xj's was loose and at certain speeds it would wiggle around causing it to run like crap.

im1986

Thanks guys for all the suggestions. I have checked the crank position sensor, and it is testing out fine, and is tight in the engine block. Still the same problem. I have had it at the shop since last Thursday and they can't figure it out either. Everything test out the way it should.

Does anyone have any more suggestions? I'm about ready to go burn the thing to the ground.

Rudy

Try resetting the computer now that you have gotten everything properly installed. You said that the original "mechanic" told you that he tried to trick the computer so maybe that's the problem.