1992 Toyota 4Runner stalls while driving

Engine Performance problem
1992 Toyota 4Runner 6 cyl Four Wheel Drive Automatic

Last night car stalled 5 times within 10 minutes of driving. Maybe I should say quit, (no sputering or fluctuation in performance).I'd have to wait over a minute before it would start again.
This morning I drove to work (20min.) Didn't stall. It's done this before (stalled at night but not in the daytime.) Started doing this a few weeks ago. I did have it stall during the day only once after driving it for some time(maybe an hour). That was a few weeks ago.
I've changed fuel filter, air filter plugs, and checked the efi relay which read wrong but the haynes manual I have doesn't show the exact same relay diagram. I checked the circuit opening relay and there was no continuity between STA and E1. (I'm not very electrically minded).
I thought it might be the lights but the ac was on too.I turned it all off and started driving in the dark but it still quit after 2 to 3 minutes. Help.