Engine Stalling (Not CPS???)

1992 Cherokee Sport, 4.0L, Automatic Trans., Part-Time 4wd. 120k miles

Bought about 3 years ago for a work truck & hunting vehicle. Since then I've started having problems with it, and I've bought a '99 XJ sport to replace it (which runs fine). So, I'd like to fix the '92, but I'm only planning on turning around and selling it as soon as I get it fixed (I don't really want to sell a car that I know has a problem).

On to the problem. . . .

Basically it shuts off (and sometimes doesn't start) at random. It appears that it can happen at any engine temperature or speed (it's happened going down the highway at 60mph, or pulling up to a stop sign with a cold engine). So basically it sounds like a bad CPS, right? Well after doing some research, I've replaced the CPS along with several other things (throttle position sensor, fuel pump, plugs, wires, cap, rotor, coil), and the problem hasn't gone away. Also, I've NEVER gotten the ECM code for bad CPS signal (can't remember the number right now, but I know I've never seen it). Generally just get code 12 (battery disconnected/power loss) although I hadn't disconnected the battery recently (however this sounds common from what I've heard).
I've checked ground straps and their connections; all look good. In fact, I added two or three additional wires to ground the battery/engine/ECM all together to make sure they were grounded; this did not help.
I haven't checked for fuel pressure (I don't have a fuel press. gauge), but even when the jeep doesn't start I can still hear the fuel pump for a couple seconds after key-on, and when I depress the valve on the fuel rail, it always squirts out a bunch.
I haven't been able to verify whether the no-start is a result of no spark or no fuel injected.
So I've got the jeep at my local mechanic (not a Jeep garage - I've had it to my local dealer and they charged me $60 for one hour to tell me that they couldn't get it to not start). My mechanic has had it not start a few times, but every time that happens, he hasn't been able to figure it out.

Does anyone have any ideas/suggestions of what to look for? I'd sure appreciate your help.

Thanks,
Wes

One of the first things I look at are loose, corroded or water logged connectors. I recently bought an old XJ, crapped out at sixty on the interstate. Third connector I checked, MAP was loose. Had some ignition issues, found a six pin (I think) intermediate connector on the left front wheel well full of water. I´ve cleaned much of the die electric goop off of the connectors, sure it keeps water out, but how the heck is 3,4, or whatever volts going to get through it.
I´ve also found bent pins and pins male or female that backed out of the connector a bit.