Anyway, he had a issue where it stopped shutting off with the key. I told him to use the shutoff lever, and he said that didn't work either. It's got a DennyT AFC delete.
Our local diesel guy got ahold of it and he found a chipped FSS plunger, and apparently the DennyT setup disabled the shutoff lever. He's never dealt with the delete before, so we're not sure if they're supposed to do that, but just putting that out there.
Anyway, on his test drive afterward, if he took the throttle past ~7/8 travel, the truck dropped down to en extremely low idle, and would die if not let completely back out. If let completely back out, the idle would pick right back up and be ready for throttle application again. It's like a switch too, completely repeatable.
He called me a week or so later, today, and said it was doing it almost right off the bat. If he pushed a little farther through the travel, it would pick up and go fine, but right off the stop it was dropping down and trying to die like before at full travel.
He's got a factory LP still, I told him to check his oil for fuel and get back to me, which he didn't do so I assume it's still good, but I don't think that's the problem. It's literally like a light switch, the second that pedal went past the 7/8 position, it went straight to dying.
Just wondering if there's anything internal in the pump that may cause such a thing. Our local dude is good with them, but he's never dealt with the delete and has no clue if it may be causing this or not.
