I'm not sure how a valve adjustment can result in white smoke, but maybe some of the experts here can chime in on that. It does appear from your description to be more of a fuel problem than a valve problem.

Try bleeding the injectors like some of the guys here say. FWIW, I've managed to adjust my valves with the hard lines on. In my case the biggest problem faced was trying to get the valve cover back on. The valves themselves were easy, with only one spring turning on me. I just jammed a screwdriver against it and it held well enough for me to adjust that valve.

You had no springs turn on you? That's the one that requires the third wrench.

__________________
1987 300TD
1984 300D
755,000 KM and going strong
BC Canada