If you are getting white smoke that means you are getting atomized fuel which means you are getting your diesel (should also smell of diesel/B99).
I would do an ohm check on each glowplug (see DIY pages) to verify that they are all WORKING...not just getting power

I think my system pulls down the voltage at the plugs to about 11-11.5V when they are working and it floats up around 12+ if the glowplugs are not working (ie no load and no Vdrop).

Unhook the wires and check each plug