I have a friend that has a question for all of you . His truck is a 1996 2500 4x4 5 speed 3.54 rears it has a hx35 turbocharger, throttle plate was slid forward by a Cummins tech.. He took it in to a place for service and noticed that when it got back it had no power. When he looked at his bill the stated that they adjusted the wastegate full open. (We still don't know why this was done and then documented.)
When he called about it they told him that they never do that and were suprised (imagine that) that it was documented on their invoice. Their advise was to back the adjustment all the way off until there was slack then tighten in 5-7 turns. He tried this and took it a few more turns until it ran good and left it.
His question is how should it be adjusted and what is the procedure to get it back like it was before.
Thanks for any help, Frank.

 

The way you are trying to adjust the preload on the control spring on the air motor on the wastegate is the way most guys try it. Once you have moved the fuel plate, it is best to simply put the truck on a dyno, load it up and tune the wastegate preload to fit the desired horsepower and EGT. Any other way is pretty crude, and will take hours of test driving and adjusting.

If you really want a fix to the wastegate issue, go see Heath Diesel at http://turbo-master.com/ and get one of their Turbo-Master controllers that replace the cumbersome air motor all together.