ISX CM870 Jake Brake Repair

[Wiseman]

What truck? How many solenoids ? Are they functioning properly ?How many positions ?
What is commanded VGT position on them ?
What's the boost @ 1700 rpm on highest setting ?
How old is your turbo ? Have you abused it with high EGT ?
Have you inspected it lately? What's the boost under full load ?
Have you done overhead adjustments after the overhaul ?
Have you checked for exhaust and boost leaks?
What do you mean by " to make them work better" ? Compared to what ?
What's in your ECM ? What was involved in the overhaul?