To cut a long story short before I had the 4kgsk installed I could hit 30ish lbs of boost over 2000 rpm but up to that she was dead could never get much boost(way less than 10 on the guage and no smoke ) at all, bottom end dead but she'd just take off after 2krpm.
Then took it back to bdpower and had them put the gsk kit in and fiddle with the fuel pump etc(fuel plate, housing and afc tweaked).... great I have a bottom end now but can't get over 20 ftlbs on the guage and minimal smoke at the lights.... so top end is dead now! fuel system, timing, injectors were all pressure checked etc.... now bd want to take out the fuel pump and send it to the lab for what they think will be a rebuild.... Are they on the right track or are they sending me on a wild goose chase for cash?
Something is clearly very wrong.... they didn't believe it could be a lack of compression... any ideas? you could save a lot of money getting that pump checked.... fuel economy is great anyway!

 

Im suffering through teh same issue. Check your intercooler boots also check teh diaphram in the AFC. i pin pointed mine down to the diaphram and after visiting imler to try and get them to fix it. they told em i was wrong and wanted to install a rebuilt pump, a diesel shop in SR is going through the same rigameroll, they wanted to take it off. i had mine bench tested and they said the pump was fine. low and behold pulled the afc off drove the truck around ran great with lots of smoke. give it a try before you drop 3 + large.

 

My experience with B-D is that they are first class and won't send you on a wild goose chase. I'm sure they checked out and eliminated the simple things first. Injection pump rebuilds and new injectors are usually the very last resort.
Cracked AFC diaphragm usually causes it to pour black smoke.

 

Thanks for the info ddestruel.... I'll certainly check that out first! As for bd I wasn't trying to knock them personally as I think they are top notch on fuel injection but they're in the business of making money first and foremost. I think a pump issue is the most obvious but I'd rather check the afc diaphragm all the same.
I am pretty sure the intake system was pressure tested aswell though..... any other things I should check first?