Rough surging idle when cold recently installed 100 horse injectors,fass 165 lift pump,s&b air intake,xdp exhaust manifold,5" mbrp exhaust, quadzilla tuner runs great under load just bouncing at idle when cold and when coasting run it for awhile and it smoothes out driving me crazy. Oh and I did replace apps sensor before I did any of the other upgrades,and reset after upgrades  wonduring what else I can check or if anyone else has experienced this thanks for any help.

8 hours ago, Shephard said:

quadzilla tuner runs great under load just bouncing at idle when cold and when coasting run it for awhile and it smoothes out driving me crazy

 

Normal. Mine does the exact same thing. After running under load and coasting to a light out of gear it will surge or lope mildly. Once you come to complete stop the lope stops. Nothing that can be done about it. In my case it mostly the pop pressure my 7 x 0.010 (150 HP) are set for at 320 bar which creates this mild lope coasting to a stop. 

 

You could switch the Quadzilla to level 0 and test again this will rule out Quadzilla issues. Even mine will continue to lope with the Quadzilla turned off. (Level 0). Strictly injectors now at that point and the ECM.

 

APPS sensor does NOT control idle. Only the ECM does. Once the IVS switch in the APPS is set for idle position then the ECM ignores the APPS completely and uses the onboard idle software of the ECM. The ECM is not programmed for large injectors so it commands a tiny amount and tends to overshot the mark and then cuts fuel. This now creates the lope. Mine will bounce 700 to 900 RPM coasting to a stop totally normal.

Edited July 25, 20195 yr by Mopar1973Man

Thanks man it's my first diesel my dad past away and left me the truck he loved that truck and I can see why. gonna continue to build it up and make it as awesome as  I can he would have liked that. Thanks again.

3 hours ago, Shephard said:

Thanks man it's my first diesel my dad past away and left me the truck he loved that truck and I can see why. gonna continue to build it up and make it as awesome as  I can he would have liked that. Thanks again.

I wish my son felt that way. I told him he was going to take me on my last ride in mine. His response was "It better be running right or I am calling ahead and telling them to dig a bigger hole".

Edited July 25, 20195 yr by dripley

2 hours ago, dripley said:

I wish my son felt that way. I told him he was going to take me on my last ride in mine. His response was "It better be running right or I am calling ahead and telling them to dig a bigger hole".

That's still way better than a lot of other ways I can think off