HELP! ! ! car not staying started!

[JonnyK]

hi guys i start my car after its recent engine swap and the car dies out! it has petrol and battery life.. so why is it cutting out? ? ?

thanks,

john
(its a 2.0 valver btw)

 

[Middo]

my punto did this, and it was a faulty fuse.

 

[GarethM]

could be the fuel return line??
altenator maybe??