I've been losing power and fuel mileage. It all started when I had a 3K gov
timing bumped to 15.5* I don't know if my turbo or my fuel. Just changed fuel filter. Turbo boost is down. Checked for air leaks, hoses ok. New waste gate. Everything I'd read on this site said that is the best way to go to increase mileage and power a bit and help cool things down. So I don't know if it could be rotten fuel lines or my turbo's gone bad. 125,000 miles.

 

Sounds to me like your timing may have slipped. The timing on my truck did that after i installed the 3k.

 

I had the timing done at the same time I had 3K spring put in.

 

still sounds like timing, ask them to dbl check it, same thing happened on a buddies truck

 

what about your gov. arm adjustment, hitting the plate in the right spot?

 

I was kinda thinking the same thing. Cause when the guy installed the spring he said that when he first tested it, it went over 4k. So he had to call a tech guy who got him straightened out. (?) I guess I'm gonna have to start studying up on mechanics. There seems to be no one around here that knows anything about performance diesels.