Howdy,
I have a 'mysterious' problem, that has stumped Ford mechanics and everyone else that I've taken it to; my 1991 Explorer will 'start' COLD,drive great as far as you want, BUT DON'T CUT THE KEY OFF!!! IT WILL NOT START 'HOT'!! You have to let it 'cool' ALL OF THE WAY BACK to COLD!!! I have driven it all day long, making stops of up to three hours,
and it never quit ONCE!! Used a lot of gas !!! We've changed all types of parts BUT nothing has worked... I put it in a 'Garage' to be looked at and all they did was 'blow' the engine up and wanted $400 for their 'work', but won't repair engine!!! They didn't fix my mysterious problem and now won't release the car, unless I pay them.. It ain't worth $400!!!! I got the tires off at night!!!!

 

Of course without having the unit here to test, I would first check 2 items, the ECT and the FPR. Cold the engine requires a rich condition to start, warm there is no need for rich. However if it induces rich when hot the engine will overload and flood, making it a non starter..... Philip

 

Have any of the folks who have looked at the truck checked the fuel pressure both when it runs and when it won't start hot? It's pretty common for cars with failing electric fuel pumps to exhibit issues when hot, including no-start conditions even though there were no symptoms up to the point of shutting off the engine. For example, it's quite common for folks in rural areas to drive 30 minutes to a shopping mall in the middle of summer, shut off the engine, shop for 20 minutes, then get back in the truck and the starter will spin the engine but it won't start. They call their spouse/child who makes the 30 minute drive in and for the heck of it, tries to start the vehicle. Low and behold it starts right up so they drive it home. No issues getting it home, but once home it may not start up after they shut it off again.

-Rod

 

Yes ROD is correct, check the fuel pressure delivery system, kind of slipped my mind....condition of getting older..... Philip