ok all I bought this burban about a month ago on the cheap. has 208k on it. The day after I bought it I installed the H/O water pump (the old one was leaking) and a oil pressure switch .6 days later made a 1600 mile round trip to take the kids to NYC. The truck ran and performed great, except I never saw it produce over 4 pounds of boost and rolled the black smoke on hard acceleration, 18.6 MPG with 6 people and so much luggage you couldn't see out the back. Since returning I diagnosed with the help of the good folks here that the wastegate was not closing. the vaccum pump is bad so for a test I put a spring on the wastegate to see if my boost would increase and black smoke decrease. It worked excellent. With the spring I was maxing out about 9.5 to 10 pounds of boost and egt never got above 1150.
Was pulling a trailer hauling mower, paying close attention to all gauges(boost, egt, coolant temp, oil pressure) cause I am still a little leery about it, and everything was good. Out of the blue it died and I drifted off the side of the road and as I came to a stop the temp. gauge started to climb and it started boiling out coolant from the overflow.
I left it overnight and returned the next day with a trailer to haul it home. I tried it and it started. it had a "kind of" knock and a lot of white smoke. I have done some diagnosing and here is what I have found.
1. lift pump works when I use a jumper to supply power to the fuse . I can bleed the system thru the "t" valve and it will start and Idle very rough with white smoke. once it dies I have to bleed it again to get it to start and it takes 10seconds or more before any fuel comes out. Is that normal or should it not remain pressurized? when should the lift pump come on with the key?
2. I had the original fuel injectors the previous owner took out when he put the marine injectors in, so I put them in and no change. He said they were good but I am not sure.

Any ideas or suggestions would be greatly appreciated.

 

I have done a little follow up and checked the codes. These are what it is showing. codes 73 and 91 thru 98.

 

PMD failure will cause The symptoms you are describing,Has the PMD been relocated ? if not do it and it is good practice to have a spare PMD in the glove box and marine injectors are no better than stock injectors when a stock injection pump is being used.