Help- my 4.2 v8 won't start!

Hi, I'm new to this forum, hope someone can help me!
I've nearly finished building my hybrid 1950 80" with a 4.2 v8 efi auto in it, from a 1993 Range Rover LSE. I've wired it all up using the original loom and ecu and everything works but it doesn't start. The engine turns over but the fuel pump doesn't pump. If you run a seperate power feed to the pump it works but there's no fuel at the plugs, as though the ecu isn't telling the injectors and fuel pump to work.
It looks like I've missed out connecting up a wire that will tell the injectors, fuel pump and ecu to "talk" to each other. If anyone has any ideas, please let me know, it's all ready to go and I can't wait to hear that v8!
Cheers, Dave.

First stop for me would be the crank sensor. Are you getting spark only and no fuel?

Also check that you have 12v to the injectors. The ECU 'fires' the injectors by switching the earth so you should see 12v at the injectors when the igniton is on.

Thanks Andy, I'll try that. Dave.