2006 ISX CM870 High Pyro, surging under load

[Rawze]

Fuel pressure on a CM870 is totally mechanical. The ECM has no control over it.

Also, 1190-F is about right as far as top end EGT's go, pre-turbo (1050-F max post turbo) in a hard pull if you try hard enough.

What you don't want is for it to run abnormally cold due to pi$$ poor programming for whatever power it is making at 100% throttle ... that is the killer of the ISX.

Of course, most people do not tend to drive their engines that hard, so they tend to back out of it when it gets to about 1050-F (950-F post turbo) or so to help the longevity of the VG turbo.