Won't run in daylight?
 

Q: I have a 1994 Jeep Grand Cherokee Laredo, just had a rebuilt trans put in, Vehicle sat in my yard for @1.5 years and was running fine (except trans). Put in new engine computer and it ran for a few days but now when the temp outside is 90+
I can only go @8-10 miles and it shuts off. At night on the way home from work it runs fine (13-15 miles). Mech thought it might be O2 sensor and disconnected it. No engine light came on, and it ran the same, stopping every 4-8 miles. I disconnected the IAT
got the eng warning light and it runs the same. What is causing it to suddenly shut off during the day and not at night? This is driving me crazy!!! HELP PLEASE ?????

Most likely candidates are coil and crankshaft position failure failing when they get hot. Not the only possibility, but common ones. Since it is somewhat predictable, you should prepare to test for spark and fuel pressure the next time it happens. One of these two things is likely dropping out on you, and knowing which one will help to narrow it down.

This^^^

If the coil is a Magnetti Marelli, replace it.