We just purchased this vehicle (Ford E-350 with a 460 V8 engine), and drove it about 4500 miles, from CA to WI and back again in July/August. Two issues:
1. After driving several hours in the heat of the day (Tmax ~100 in July, ~90 in August), the engine cut out and it took about half an hour to start again. Fuel level was between 3/8 and 5/8 tank. The problem didn’t seem to occur with a full tank. We think the fuel pump was replaced in 2003, we assume as the result of a technical bulletin. We added injector cleaner with about every 100 gallons.
2. We towed a Hyundai Accent on a tow dolly on this trip. It seemed that all the other RVs on the road were trucking along at 70+ mph without losing speed on the uphill grades. We would slow to 30-45 mph. Because of this, the travel time took 2 extra days.
Any wisdom/advice for these two problems?
If the fuel shut off and then wouldn’t allow a hot start, I would suspect a vapor lock.
The starter turned the engine over at the normal speed when it was hot?
Fuel filter and air filters clean?
Any air intake vacuum leaks?
You MAY have an emissions fault somewhere.
If you haven’t already researched, ensure the ‘toad’ isn’t too heavy for this rig to pull at highway speed.
Check the specs and don’t forget to add the hitch and dolly weights.
We have what sounds like the exact same problem. We are travelers too with a 1992 Airstream class B motorhome. Ours started in AZ climing moutains in the Tonto Basin and repeated a few times in the moutains of Or, Wa,. Semms to be getting worse now; happened last week in Odessa TX in 80 deg. temps. in traffic. Ran ok after getting out of town. Also noticed the fuel consumption is getting poor. Help, let us know if you solved the riddle.