For this specific problem, I had an interesting development today. After reading some very informative posts on this forum and newsgroups, I encountered some folks who had typically replaced the 3 electrolytic capacitors that filter the voltage running through the computer. Apparently these things fail fairly easily after 5-10 years. So I took a gamble and removed my ecm (computer) from my 95 YJ and opened it up. It was obviously made not to be serviceable in that the circuit board was immersed in an inch of semi-clear reddish rubberized waterproof insulation. I could see the 3 capacitors whose ends were protruding from the insulation. 2 of the 3 were cracked and oxidized. Visually bad. I painstakenly removed the rubber insulation from around each 3 capacitors (with an exacto blade) and then carefully used a dremel tool cutoff wheel to cut shallow access holes through the plastic housing on the other side (estimating where the Capacitor locations where). I carefully cut-away the rubberized insulation around the capacitor leads on the opposite side (bottom). I then de-soldered the leads and removed the old capacitors. All 3 CAPS were the same rating 20 micro farad rated at 25 volts. I soldered in radio-shack replacement caps 22 micro farad rated at 35 volts. (higher voltage is OK - Not lower). I noted the orientation of the original caps and was careful not to install the CAPS backwards, they will fail (could explode). For a quick test I took the unsealed unit with the new caps out to the YJ - and it fired right up. Fixed the problem!
The jury is still out on how long this will last, based on my solder job, the quality of the CAPS and other factors. But it would seem I repaired my computer (that the dealer wanted $600 for) - with $1.50 worth of radio shack electrolytic caps and 3 hours of my time. I will follow-up in the next few days with an update. This evening I have covered the exposed caps and cut-away areas with a clear water-proof Goop type glue. It should be better than the original (and existing) waterproof insulation. I hope this might help someone.