97 12.7 idle issues

Ok thanks I will show this to my shop tomorrow

 

DDEC4

 

It's a 97 ddec4 12.7 in a 98 century

 

Which model is it?

 

So what does half engine mode do?

 

Its been a while but I think it only fires on 3 cylinders until the engine warms up. My old man had a DDEC 4 with that feature. It smoothed out considerably once it warmed up enough to start firing on all 6.

 

Truck is a century 120

 

First if it was on half engine warm up, that wont log a coded.


Second them have poor ground studs from the factory at starter and battery box. I would expect them to have been changed by not. But its possible. They did not bolt it thru the frame. The just counter sunk the stud and tack welded it. Corrosion builds and loses ground. Normally the power steering hoses melt first being next path to ground. Dont re drill next to stud, because it's in the heat treated area. Go to the center of the frame rail and drill thru and bolt ground down to it.

And look up in wheel well for APADs. That was the year it was mounted up above RF inner wheel well.

 

Which model engine is it?
Bk, pk, tk, mk, gk, hk...?

 

By running on 3 cylinders and advancing the timing it increases peak pressure and makes for a more complete burn. It eliminates a lot of the white smoke on start up. It supposedly warms the engine up faster but that's debatable