No Negative Voltage To Fuel Injectors - Looking For Causes

[Nacho]

Just checked the fuel injector power and it doesn't appear to have any voltage to the negative terminal. Just wondering if anyone knows if it's normal. If not could it be caused by:

a) ECU

b) Immobiliser

c) Other

Thoughts anyone?

[payaya]

So the injector is not ticking at all when started?

[Bennoz]

I'd piss that immobiliser off. Rip it out & bridge the main immobiliser circuit(s)

[Nacho]

Yeah it does sound like it's now the immobiliser. I'll give a bit of background though coz this ties into my fuel and spark and no fire issue.

Had spark, and had fuel coming through but still wouldn't start. Did some tracing and turns out I left the GPX ECU (car is a GR) installed when I was originally whacking a MIVEC engine in but changed my mind. After some further troubleshooting I was assuming the bastard wasn't starting since it was looking for a MAP instead of a MAF reading.

So put the correct ECU in (GR) now and all of a sudden I've lost fuel going in again. Check the voltage across fuel injector terminals when cranking, got a voltage on the + but none on the -

That's pretty much all the info I can give. I'm assuming there should be some voltage coming through the negative terminal too.