79 300td will not start

I just bought a used 1979 300td Wagon which started up great when I test drove and picked it up. The next morning it would not start but it does crank and lets noticeable smoke out of the tailpipe. The overnight temperature was about 10C, I plugged in the block heater for a few hours before my second attempt and still no luck. The battery has strong charge, the glow light comes on and the glow plugs were just serviced. I know the vales need are in need of an adjustment. Could someone tell me if it is compression related and suggest some trouble shooting and advice??? Thanks.