I have an om617A in my s10 and latley i ran into a problem with it returning to idle. heres my situation, after driving the truck till it gets to temperature it seems fine but after that when you left off the throttle and go to stop the motor will idle down very low sometimes killing sometimes not but then it will shoot back up to regular idle if it doesnt die. any ideas what i could have to do??? would adjusting the valves help with this? I have never messed with them.

mods to motor:
injection pump turned up to 1/4 turn
waste gate line plugged off for 20lbs of boost.

 

From what I have gathered about the IP, you have to balance out everything when you start turning screws. There is no one power screw on a merceds IP. If you turn what ever screw back down, you will probably restore your idle to normal.

Try reading this Bosch M and Mw pump theory

 

I adjusted the full load adjustment screw. only 1/4 turn

 

the full load adjust screw shouldnt cause it i cranked mine all the way and it still idles fine