Help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!

I have just completed a headgasket replacement on a RR 1989 3.5efi I have put everything back and have fuel in the car but she just wont fire up she tries to but wont tried some easy start and got her to fire up but as soon as i stop spraying she just dies i have checked spark and fuel supply and all seems well strong spark and there is fuel in the fuel line i am at a lose can anyone help ?

Has the car been stood for some time whilst the repair took place.Oil can drain from the Hydraulic tappets over time and it takes ages to prime them.If the tappets are devoid of oil,they can't open the valves enough.If you have done an oil change there is a possibility the oil pump may need priming.Remove the cover plate and pack it full of Vaseline around the gears-NOT GREASE!!,refit the cover and give it a go-make sure you have a fully charged battery first