got greyish smoke on start up for about 1 minute then it clears, what can it be its not valve stem oil seals.

grey is normally fuel, and if its going after one minute that sounds like warmup fuelling.

What ecu are you running I.e. is it your mapping, sounds like warmup correction is a bit ott.

1) ? steam due to a blown head gasket

2)Burning oil due to a worn piston rings


To check a leak down test and a coolant CO test should help...

Megasquirt

Not loosing any water or oil also had new head gasket

Is the motor cold or warm on startup? If it is warm (like going out for a blat and stopping for lunch. Then starting the motor and getting smoke) it sounds like valve guides. Russ

Only smokes from cold

back off the temp correction fuel map.

I've never mapped megasquirt stuff, but all the normal ecu's have a temp compensation map which adds a percentage fuel over the main speed/load map depending on the coolant temp (no doubt teaching you to suck eggs here) but just try backing all the temp correction map off, and also check that the coolant temp sensor is working ok.

Thanks will have a go, it does make sence as the colder it is the worse it is