Bf's S12 wont start

[Unity]

hey folks, my bf is in total desperation now, cos his wee silvia wont start. He’s changed the external fuel tank and intank pump to an internal alloy tank with a seperate swirl pot and external fuel pump. The pump is priming and he’s getting healthy 45psi fuel pressure at engine and he’s getting a spark but no engine start Done the whole diagnostics test and shes coming up error 22 fuel pump problem but shes definely getting fuel at the engine, so god i hope someone on here knows whats the prob? He’s thinking ecu thinks no fuel pump so not sending a signal to fire the injectors cos plugs are staying dry. He’s found 2 wires to power pump in boot and 2 wires to power fuel gauge but theres an orange wire not connected to anything. Is this the prob? Is the ecu looking a resistance on this wire? Someone please put him out of his misery cos this wee car has never seen a welder and has only 68k and its a cryin shame to give up on her. Any help will be greatly appreciated

ps his silvia is 1986 if that makes any difference. thanks again

[navysnail]

use a noid light and see if the injectors are pulsing.

was the orange wire connected to anything before?