Question for diesel gurus (strange failure 6.9idi)

67charger383 said
Haven’t started my truck in about a week.
It was 50* out so I didn’t use the block heater.

(it’s a ‘87 F350 dually. 6.9 idi/t19 4 speed)

Started right up after a few cranks, then I had it idling for 5ish minutes. I do this a lot with this truck because it doesn’t have tags yet.
Had it warmed up and went into low idle like it should.

Anyway, it randomly started revving up without me touching the pedal, and I immediately killed it with the ignition. Only did this for about 1-2 seconds before I cut it off.

Looked over everything, no leaks, didn’t blow up, nothing got sucked in the intake.

waited about 5 minutes and went to start it again, seemed like it was cranking faster than normal so I stopped.

What the hell happened and how do I fix it?
It’s a low mileage truck, but I suspect it might be injection pump failure or lift pump failure?

I worked at the Navistar Indy Engine plant back when the 6.9 was built. I can guarantee you that engine saved the employment of a couple of thousand employees directly and untold thousands indirectly. With that said, to your problem,,,
Check the fuel filter and air filter, an unsteady idle is an indication that the motor is starving for fuel or air.
If your truck has OBD II, check to see if it has set any codes. Your engine is mechanical FI, so it may not have OBD.
There are a lot of 6.9’s still in service so if you don’t get good direction here at FABO look for help at a 6.9 diesel forum.
www.binderplanet.com
Is forum that deals with all products made by IH/Navistar.