oh so the ground wires are going to the ECU, so no wonder why i wouldnt of got light on it right? or wrong?

so basically all i need to do

test wires from battery to injectors if thats active.. pretty easy just the regular wire test right..

then ill need to check the ground wires from injectors to ECU do a test on these wires using the multimeter or the same tester to see if its acive (dont quite get how ill test these wires)

i dont get what mean by "when u touch the probes to both ends of the wire(get a long piece of spare wire to join at one end to do this simply,so u can form a loop)"

im not familiar with this stuff aye!