Drove the Expy from SoCal to Vegas. Out of Baker (for those not familiar with this drive), there's a 15-mile or so climb with about 2K in elevation gain, all done in 100+ degree temps. Hell yes, I had the AC on.

Near the top of the grade, the tach dropped and the gas pedal was non-responsive. It quit running just as I got onto the shoulder of the road.

After 5 minutes of explaining to my wife why we were "cooling off" where the semis would rather we weren't, we restarted and managed about a half mile before the engine quit again.

Another couple minutes waiting, with an elaboration on the subject of vapor lock, and we gave it another go, cresting the hill.

Never experienced vapor lock but the symptoms clicked with my understanding of what it I think it is.

Can anyone tell me how to prevent this from happening again?

 

Vapor lock is non-existent with fuel injection. It was a condition that plagued carbureted engines. Your problem sounds more like your fuel pump kept shutting down. A bad pump will cut out more-so when the fuel tank is less than 1/2 full. Try the same run again with a full tank and I doubt you'll have the problem. If that happens, you'll need to replace the fuel pump at your earliest convenience.

 

While your at it, change your fuel filter also.

 

Alloro is correct, you did not experience vapor lock. Vehicles with carburetors typically run about 5-7psi of fuel pressure. Your FI system runs more like 30-40psi which keeps the fuel from going to vapor in the lines.

 

The old Mopars I grew up with were poster children for vapor lock. It happens when the engine is shut down and the heat vaporizes the fuel in the line near the carburetor. I never had it happen when the engine was running.

 

What do you think you're doing? You're not supposed to agree with me! You're suppose to say my advice was not helpful then stop posting in this thread.

 

Replicating the conditions is a 400 mile r/t jaunt and its being the definitive test seems iffy. To date, the failure has been random...is there any more precise way to test for a goner?

And, preparing for the worst, is there a DIY on fuel pump replacement?

 

If you are pretty certain it is fuel related you could carry an inexpensive tire pressure gage and when it happens next, check the fuel pressure in the fuel rail. I would change the inline fuel filter right away and hope for the best. You might have bought a tankful of dirty fuel and clogged the filter.

 

Appreciated. Now I know what I'm doin' on Saturday.

 

Like 45 guy, I was cresting a summit in CO at 14,000 and my 2001 Expy cut out. There was a LOT of backpressure in the fuel line. After I opened the cap and let it disapate, it was ok. I consistenly get a code 0442 also. It has a new Ford gas cap, the fuel pump and filter is only one year old.