help please, I am walking too much

99 toyota tacoma 3.4 17000 miles, mostly a hunting truck, cranks good,runs good but when gets hot it shuts off then after awhile it crank back. Have put in new fuel pump and filter ckecked according to book: relays circut opening, efi, switch, but when its hot pump only runs with starter turning over. After cooling it works right. Took to mechanic , he checked crank sensor, ecm,drove it aroung short distances said he could not find nothing, I picked up drove it 6 miles it quit half mile from drivway, let it cool half hour it cranked back. . . Shows no codes. Guess I will have to fix it myself, really hate to junk it out, can anybody help?

 

I'll guess coolant temp sensor but I may be wrong. Check the EGR valve is functioning correctly. Maybe find another ECM to swap and see if it goes away. Sorry I'm not much help. Try another fuel pump relay.