98 6.5 TD Idle hunting problems!!!
 

Well, I am at a loss of words... here is what I am dealing with...

Today I was driving my truck, 98 K3500 w/ brand new (less than 2500 miles) motor, I/P injectors, whole 9 yards. I replaced everything a month ago. It was running beautifully. I pulled into a station to filll up. Filled up and when I started the truck back up the idle was going from 600 RPMS to around 2000 RPMS, back and forth, back and forth. When I step on the pedal, no response at all. There is no check engine light or anything and I am smoking like crazy (white smoke initially then turns black when it goes up to the high end of the reving). When I shut the motor off it starts up, but as soon as I give it any throttle, it goes back to reveing between 600 - 2000 again, and the throttle is again unresponsive...

What do I check first? Any ideas. It is a brand new PMD, replaced with a fresh rebuilt IP.

I havent trouble shot at all because I have no idea where to begin. Any help would be a Godsend. Thank you.:scare2:

I'm no expert , but it sounds like the electronic throttle is not performing correctly , especially since you've replaced everything else.

Sounds like the i/p is bad. There is a valve inside the i/p I can't remember what it is called that goes bad and causes this.

Well, it is a freshly rebuilt IP. It should still be under warranty, but I want to make sure of what it is before I go saying it is a bad IP. Is the electronic throttle separate from the IP, or is it built into it? I need a way to troubleshoot this without just buying new parts.

Any suggestions?

Anyone else have any ideas?

Injection pump. I been there done that several times with the 5.7 Olds diesel.