Last week I bought my 98 k3500 with 6.5 turbo and 5 speed trans. I drove it for a week and refueled. About 4 miles later I got a bad miss with white smoke. I did some sniffing and found it was likely a bad injector. While idling cracked the fuel line to number 1 3 5 7 with no change. cracked 2 and the smoke stopped. Tightened. Smoke again. Repeated this 3 more times. I found my injector. with some patience I was able to replace it with a brand new one from advance auto. Got it back together. No change. Cracked the line again. No smoke. Tightened it. Smoke. I'm not a diesel guy so in pretty much lost and going by what I find on these forums. What should my next course of action be?