I have a 93 motorhome with a late 92 Ford 460 EFI engine. Up to now this engine has performed flawlessly. This summer while traveling in 100 plus degree temperatures, and after driving about 350 miles, the engine suddenly lost power after cresting the top of a hill after I let off the gas. The fuel tank was getting low, but it still had about an eighth of a tank remaining of the 75 gallon capacity. Had it towed to a shop and they said it was a plugged fuel filter. Filled up the tank and went on our way. Two days later in 106 degree temp with a half tank of fuel, and after letting off the gas to negotiate a corner, it died again. After about 5 hours of letting it all cool down, it did start. After this we drove in the early, cool hours and did not have another problem. Any ideas on what would cause the engine to die upon deceleration after climbing some rather steep grades without any problems. Push it hard and it ran great, let off the gas and it dies? Any ideas would be greatly appreciated.

Thank you.

 

We had that problem in our F350 with a 460. My dad said it was some tube that went to the EGR valve that was split in the middle. He couldnt remember what it was called. Hope this helps

 

It may be fuel vapoization(vapor lock) in the fuel rails. You push it hard, heating up the dog house and using a lot of fuel, then when you ease off, like going down hill the fuel is not moving thru the rails, allowing it to heat up and "vaporize".

Earlier Ford models had a fan placed to blow cool air over the rail on the 4.9 I think, 'cause this combo experienced this problem.

Something to think about.