puzzled

[Ace 1926]

I have a real head scratcher. 98 Explorer XLT 4.0 sohc runs great except on 90 degree plus days here in So Cal. It will just stop running with NO code being thrown. Let it cool of an hour ( or 40 miles on a tow truck) and it will start and run great again. Fuel pressure is good when its running. The Dealer is lost without a code so my personal mechanic took a stab at it with fuel pump, relay , filter. Got a good hot day to take it out and give it a test and sure enough about and hour it just died not a cough not a sputter. The mechanic and I are now thinking something electronic heat soaking and shutting down or going open but where to start? The master bus under the hood with fuses was very hot to the touch this last go around. pushed it into the shade , sat and cussed Henry Ford for 90 minutes and it started up and has run fine since.I have had it die when backing out of a parking space on hot days in the past but it always starts then. It's got low mileage and in good shape and is a good fit for us so I hate to ditch the thing. Any input would be appreciated.. Thank you

 

[koda2000]

If the "bus" (AKA the power distribution box) is getting really hot, you have a bad electrical connection somewhere. Start by removing and cleaning your battery terminals, then examine the cables to see if they appear lumpy/corroded. Next check the electrical connections at the starter and alternator to make sure they're clean and tight. You also want to check the connection of the Mega fuse at the power distribution box. A bad/loose connection will cause wires to get really hot. That's very likely the source of your problem.