Hey I pulled an engine from a nissan prefer to have complete nissan... and put it in my vl and used my old auto wireing loom and bridged the purple wires.. anyway.. my trouble is that I brought a cas replaced it because thought that was my problem it has all new leads & plugs dissy cap my computer dosent light up when I first turn ignition on.. iv tryed 2 computers.. really need help as im 2 years into my projects it basically rdw but just need it to start.. its driving me insane.. please help...

Getting the engine to start is a little complex.. lets go back to basics, check the engine and body have been correctly electrically grounded & clean shiny metal; Battery to Body, Battery to engine block, intake or head to engine block. then check that 12volt is present when the ignition is turned on at these locations on the ECU connector; pin 114 pin 35 pin 34 pin 27 pink wire on transistor pink wire on coil. bonus check; pin 9 doesn't need to have 12volts when the key switch is in START position but it helps ECU know when expect the engine to Start so it can throw up all the other Error codes. Error codes such as CAS signal & AFM etc. to work correctly it needs be connected to the Starter motor solenoid 12volt power feed to get this 12volt signal input to the ECU. so if the car cranks over but 12V isn't on pin 9 during cranking, it's not connected to the starter solenoid circuit. if you can't figure out what the pin numbers are on the ECU, open up the spare one and read them from the inside of the ECU connectors. You'll work it out more easily if draw yourself a diagram facing from the other side.