First post here, thought I wasn’t going to work on 22r’s anymore, but here I am..
The truck is a 1990 22re 4wd 5spd. It belongs to my neighbor. It was running perfectly until he parked it for 2 months.

This problem happened first start after sitting and every single time since. The truck starts and runs exactly like it should until it warms up, (about 15 mins sitting at idle) then just dies and will not restart again until cold. After quitting, starting fluid will make it run for a few seconds, another squirt and another few seconds.. It has spark for sure, not getting fuel for some reason. Pump and filter have been replaced. Hot wiring the pump makes no difference, pinched the return hose, no change. So I’m ruling out supply and regulator. It seems like the injectors just stop opening. What makes them decide to shut down and not open? It runs perfect when it’s cold, idles smooth, revs smooth, every single time. Does the temp sensor have control over the injectors? The temp gauge works, I feel like the cold start injector is working properly.. (starting fluid helps, engine doesn’t seem to be flooding) The coil and ignitor have been swapped, no change. A bunch of connections have been cleaned and/or checked, no change. Jiggled all the wires I could reach, no change. It’s super consistent, starts and runs perfect, gets warm, dies, wont start again until cold.. I’ve read all the posts I can find with anything similar, everybody’s issue seems to be hard starting once warm, not refusing to start AT ALL once warm..
Anybody deal with this problem before? Any ideas would be appreciated, just trying to help the neighbor get his junk on the road again.