I just recently purchased a 06' unmoded quad cab 4x4 3500 with 155,000. I have had the truck for about 1 year with no problems except the clutch. I replaced it with a valair unit stageII. Up until the truck acted up, the engine never had and problems or warning signs. The engine had very large plumes of white smoke with clunking noise with it, no power. No check engine light or no codes (used solis snap on scanner).
The only thing that was strange is that on the injector kill test #2 had no effection it running bad verus the other five cylinders. That injector was replaced with a known good unit. It idled a little better but still the smoke and no power is there. I guess the next thing is a compression check. Iam a loss to what to check next.

 

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