1998 Explorer - Dies when hot

[elrothir]

I've got a 1998 Explorer, 4.0 SOHC with @ 150,000 miles on it. Recently it's been dying when it gets hot out. It seemed to run fine in the morning or when it's first started up, but it's been super hot lately, so didn't make it long before dying. It seems to start back up, but has no power and then dies again. Fuel tank was just filled and don't think it threw any CEL codes.

I think it might be the fuel pump but I just replaced that a year or two ago(but could have gone bad anyway). Any other things to check?

Unfortunately, it's with my son in another state, so I can't get to it easily. Might just have to put it out to pasture since not sure it's worth trying to trailer back home. If anyone's near Denver and interested, let me know!

Thanks for any suggestions!

 

[410Fortune]

You need to check fuel rail pressure

When it dies next time try listening for the fuel pump? fuel pump in the tank should come on for a second or two each time you turn the key to "run"
If you do not hear the pump try replacing the fuel pump relay with the one next to it, see if the pump comes on.
The theory here is that the fuel pump gets hot and quits (happens alot)
Or the fuel pump relay is getting hot and quits (happens alot)

The auto parts store fuel pumps like Airtex brand do not last very well, especially if you are somebody who likes to keep less then half tank of fuel alot. (fuel in the tank cools the pump)

let us know what he finds out

 

[elrothir]

Thanks 410. I'll have him try the relay.
Before replacing the fuel pump last year, we probably did run the tank pretty low. When I had to replace the pump, I learned that it was bad to let it get below quarter tank, so we tried to avoid that from then on. My son did fill the tank yesterday and it still had issues, so maybe it is the relay.
The replacement pump was from Carquest and was a Delphi. Not sure if Delphi is good or bad.
He'll be out of town this weekend, so he won't be able to try anything out until next week. But not sure how much work we'll put into it since it's 20 years old and he's not tooo mechanically inclined. But I really hate to junk it since it's in really great shape.

Thanks again!

 

[410Fortune]

delphi is pretty good! that maybe why you got 2 years from it

Heat is a killer
The first thing we suspect when you say it "dies when hot, and restarts later when cool" is a failing fuel pump
Easy enough to check, when it dies you likely will not hear the pump run OR it will sound very very weak
You can listen for it under the drivers seat or put your ear to the filler neck with the fuel fill cap off
The best way to test is with a fuel pressure gauge hooked to the fuel rail, if that is possible
Now a 98 can have one fuel line or two, since in the middle of 98 is when they went from a return style fuel system (two fuel lines) to a returnless (single fuel line)
the difference is the rail pressure, the 91-97.5 trucks should have 36-42 psi at the rail, the 98-01 trucks should have 60-64 psi at the rail plus or minus

Let us know what he find out!