is it carbs or injectors ?

carb check floats and jets

injectors check flow

you say your getting plenty of fuel guessing thats down the at the spark plugs?

try a bit of WD40 down the spark holes before cranking

Thanks for all the input. 3.9 EFi known as 14CUX system.

I've tried easy start and that was no good.

The plugs are quite wet when taken out after cranking.  405 AB exec seats Baltic and Cirrus
93 RR Classic efi

Remember it's easier to get forgiveness than permission!

Gone in order:
4.4 TDV8 SE - gone to a good home
93 Classic hard dash Plymouth Blue
03 L322 Oslo Blue
2000 Disco TD5 ES Epsom Green
98 P38 Rioja Red
89 Classic Cairngorm Brown