Power loss - RPMs go to idle. Let off pedal, step back on power returns.

[afinepoint]

01 F350 crew 4 x 4 dually 7.3L. 153k miles. Modified big truck air filter.

Today on the highway the RPMs dropped to idle. The truck coasted and there was no throttle response. I let off the pedal pressed down and engine responded normally. About a mile later it happened again. I made it to my destination and parked the truck.

It's acting like the fuel pump is failing.

Bowl and in line fuel filters recently replaced. Oil changed a few months ago.

The GEM has a ground so the batteries remain disconnected when parked. This has been the case for years. The cam position sensor was replaced years ago per recall.

Thoughts?

Oh, the truck was hit while parked two months ago and the drive on the highway was the first time it's been moved more at speed and more than a couple of hundred miles. It was struck in the rear outside wheel. Destroying the wheel and breaking the leaf spring on that side. The truck was stuck with enough force to move it several feet and putting it up on the curb. I was driving it back to the body shop after the springs were replaced when it began acting up.

 

[Shaggy]

Today on the highway the RPMs dropped to idle. The truck coasted and there was no throttle response. I let off the pedal pressed down and engine responded normally.

That sounds a lot like the accelerator pedal sensor (APPS), the 7.3 is known for dropping to idle and then coming back when you let off and step on it again. Might be worth checking for codes first. Let us know what you find.