Engine Dies Intermitently

I have a 94 XJ with a 4.0 with an automatic trans. I was out cruising back roads this weekend exploring for new places to go. I was going along about 35mph when all of a sudden my engine dies. No warning, no stutter it just flat out dies. As I coast I tap the gas, the engine kicks back on and away I go. 5 minutes later it dies again going the same speed. This time I am not able to get it back going by tapping the gas. I coast to the nearest pull off. Put it in park try and crank it over. It fires right up. I was finally able to limp it home this way. It did this 2 more times at 60 mph before I got it home.

I thought it was the CPS. So installed a new one thinking it would cure the problem. It didnt. Still doing the same thing. It is not throwing a check engine light. All my guages still work when this happens. It doesnt buck and try to stay running. The motor just completely shuts off.

I am good with a wrench, but not so well with electrical. Just wondering on where I should look first.

Thanks

I will add.
I put a MSD coil in it about 3 months ago.
A new motor 6 months ago.
Bored throttle body.
Ford injectors.
Cold air intake.
The Jeep runs amazing.

Except for when it just shuts off randomly. Never had any other problems.
Maybe I will try and throw my OEM coil back in. It feels like it is electrical. Maybe a spark issue?

check the tps. if the computer cant tell where the throttle is then it doesn't know how much fuel to give

A/C equipped?

One elk season my full-size Bronco started doing that same thing. I got out and had my buddy start the engine and I observed. It was the A/C clutch had started to fail and would engage and stall out the engine. Cut the v-belt and had a good hunt--we took 9 cow elk out of 12 tags that year.

Anyway, any belt driven accessory can start failing and put too much drag on the engine at low RPMs and stall it--the P/S, A/C. Pull the serpentine belt and check the bearings/bushings on the accessories.

Heh, I had a problem like the one you describe Joe, except I was hunting pig, and it was my alternator on my suburban... Oh and it had a serpentine belt, rather had a serpentine belt which was eaten by the bearings dying in the alternator. Thankfully, we had a second vehicle to get to town with.

Anyways back to the OP.

Before swapping coils I would definitely check to make sure you're getting spark.

I think the TPS is a place to start looking, unfortunately, while I just picked up a '91 HO, I havn't had too much time to work on it. So I don't remember if it also has an idle solenoid. On the older renix XJ's intermittent sensor problems can cause exactly what you describe, and the throttle solenoid and throttle sensors are often root causes and a good place to start, especially with the symptoms you describe.

The Federal Mogul stock-style timing set didn't last 20K in my stroker. When I swapped it out for the Rollmaster set, I also swapped in a new MSD coil. On the test drive around the block, the Jeep died. The MSD didn't even last 3 mins! I've also had an Accel coil fail. I have a reg ole BWD in there now.

I appreciate the help guys. I think I have tracked the problem down. I got under the hood with the engine running and did a wiggle test on every wire under the hood. I finally got it to die. I tried again on the same set of wires and was able to kill the motor every time now.

Its the same group of wires that run from a big gray plug under the main relay box behind the battery. From the plug, the wires run to the distributor, the coil and to a rubber block on the back of the alternator. It might even be the plug that goes into the coil. I noticed a break in the black wire that runs into the plug.

think I will hit the junkyard tomorrow after work and find me the best looking one I can find. Ill let you guys know what I come up with..

With those symptoms and what you have found; my money is on the coil or the wiring going to it.
Several years ago I also had a problem with the engine cutting out and found it to be the 12VDC coil leads being worn thru and contacting each other. Once I repaired the wires; the problem was gone.

I got off work and headed to the junkyard. Found the nicest XJ and pulled the wiring I needed. Got it for 10 bucks. Installed it about an hour ago. All seems good. The real test will be tomorrow when it gets driven. I will keep you guys posted on my findings.