Grey smoke and rough idle

[CitroJim]

That's proof positive it's not combusting then John. I'd suspect the glows just can't get enough heat in there to get it hot enough to allow the WVO to get going...

Might be worth checking the valve clearances; a tight valve on a stone cold engine (when clearances are at their minimum) can give rise to the same set of symptoms...

[jgra1]

thanks Jim,, will check the valves soon enough..

I suspect its the glows as usual.. thing is, I have a feeling that tomorrow morning it could be colder and maybe it will start better.. it's just a bit random, or is that just what i am telling myself, to avoid more GP work

hence the voltmeter etc.. just to cornfirm what I think I already know..