Hi I just finished a swap in my 1991 Chevy in which I put a 24 valve cummins and now when I go to start the truck it revs way up and then right to I’d and this all happens within like a second or 2 and I’m not sure what it is, has anyone experienced anything like this, any help is appreciated!

Oley. Welcome. I get through there quite a bit. Beautiful area.

Does it rev up all the way and then settle in to an idle and work fine after that? If so I would think a leaky injector(s) or turbo leaking fuel or oil respectively over time and burning that off on startup. A form of a runaway.

A 24v in a swap can be a chore with the electronics. How are you controlling the APPS? Not sure if you have a way to read codes but if you can start there.

Edited April 14, 20205 yr by dave110

Good points...