First Jeep, not new to wrenching on stuff though.

Stats:

1991 XJ 4x4 M/T
296,000 + miles on original motor and trans

Issue: Intermittent stumble at idle, intermittent rough acceleration.

Diagnosis: Bushing failure within distributor allowing oil into distributor cap.

I ordered a new complete distributor through the local parts store, and following the procedure in the FSM, installed it. After literally a day and a half trying to get the darn distributor indexed properly (without success) I re-installed the old distributor- it installed first go, without issue, and allowed the truck to fire right up.

I then removed the old distributor to compare the two side-by-side.

Upon closer inspection, the camshaft driven gear on the distributors are not timed the same between the two distributors- the 'new distributor' is about 5-10* advanced from the original. Needless to say, I have returned this distributor to the store from whence it came.

Question(s):
1: Is the distributor I received for a different year motor?
2: I have read that there are some fitment issues using parts from different year engines- where can find one a date code on the 4.0 engines?
3: Any recommendations for replacement distributors? I would prefer new to rebuilt, but if people have had good success using the reman units, I'd be okay with it...

 

No. The trouble is all distributor and cam manufactures no longer index the drive gear. The mounting foot plate on the distributor will almost never line up with the hole in the block. Easy fix is to install the distributor as the FSM explains (insert pin in cam sensor while installing the dizzy), you'll just need to put it in a position where the foot plate doesn't interfear with the mounting bolt. You can put that distributor in any positon as long as you have the pin installed through the cam sensor through the distributor body and you just need to keep you firing order correct. Some people grind off the foot plate (I did) while others just turn it to a position where it doesn't get in the way.

Remember, you can only install the distributor in a different position if you have the cam sensor (and shaft) locked in place with the guide pin through the distributor body. This is what keeps it timed correctly. DO NOT move it one tooth forward or backwards to get the mounting holes to line up.

The distributor you had was fine, and you probably wont find a distributor anywhere that has the drive gear indexed correctly.

 

Cherockee-

Thanks for the reply, but I can't find *any* info about the procedure described below in my FSM (for a 1994 XJ).

Insert pin in cam sensor? Grind ears off distributor? Do you have a link to this procedure?

Silly me for thinking a BRAND NEW distributor would work, out of the box, without requiring modification which is sure to void the warrantee.

Jeep wants $390 for theirs....

 

Check page 5, post #69. Does your distribuor look lik this with the cam sensor removed?
https://www.cherokeeforum.com/f2/nee...please-113038/