after valley gasket replaced?......

hi guys after replacing my valley gasket few day's ago i did a oil and filter change yesterday,i drove aprox 4mile's yesterday and now its missfiring am i right in saying that due to the oil being clean/new when it got hot it become's more viscuous and would allow to be drawn into the intake if the v gasket was leaking?
would this cause a miss fire it was sound for 5 miles again tody but when get's warmer does it again?
also a sign of blue smoke this morning indicating oil in cylinder?

well stripped it all back down and all seem's well so re assembled to find again ran ok took round block few times all ok went to local offlicence coming back its starts again........aprox 2 miles and its started ahhhhhhhhhh help

Are you sure it is blue smoke and not caused by a coolant leak into the inlet? the oil change might be just coinsidence

Has your coolant level dropped at all or the exhaust blowing excessive moisture?

Is the misfire ignition side or injection side?

Would suggest check ignition side first. I am right in thinking you're running a P38? I'm not too good on them but it may well be something daft, a loose connection somewhere perhaps?

Might sound like a stupid question-are the right electrical plugs on the injectors, especially on the right bank? It's easy to fit the temperature sensor plug on to the first injector instead. Sometimes the colour of the plug darkens with age & heat from the engine. I did it once on my old 3.9, she started and then ran like a bag of bolts when warm.

sorry guy's sorted now was trying to run on gas even though not supposed to yet the blue must have been bore wash due to keep cranking as not happended since rectifiying gas cheers