NEED HELP! vp running rough at startup when cold. blown head?

[sirsmokeallot]

My vp commodore runs extreamly rough upon 1st startup after the car has been sitting for a while(overnight). the revs jump to 4000+, lots of white smoke comes out exhasut. car violently shakes around if i put my foot down. sometimes the car stalls and engine light comes up, after 2nd startup it goes away.
once the car warms up it will run without fault for the rest of the day.

my thoughts are...
Head gasket (rare but could happen)
some sort of water/coolent leaking in
vapour hoses
plugs and leads done recently.

Any help on how to diagnose this problem would be greatly appreciated!

[sirsmokeallot]

starting to think leaking injectors either fuel or water. gonna rip em out and send off for inspection