VR V6 Injector wiring

[gazza]

Hi all i need to know if the plugs on the injectors wires are both live. I know one is live a one goes to the computer which is the pulse wire is it live. When i turn on the ignition and test the wires they are both live i cant start the car because it floods the engine with fuel this is a vr v6 commodore the injectors have been reco by aussie injectors. Thanks Gary.

[Charlescrown]

They will both show 12V untill the ECU grounds then out.

[VK_3800]

As above the ECU provides the ground side. You can un-plug and run a test light instead to see what's happening.

[gazza]

hi thanks the replys. I did a test with a test light and with the computer unplugged and plugged back in and it still shows power to the injector plug when i crank the engine over the wire from the computer does pulsate and when i stop turning the engine over it is live again so is that the way it works or do i have a problem. Thanks Gary.

[VK_3800]

It should only pulse when commanded by the ECU, the light should not be on at any other time.

edit: that's assuming you have the light connected to both terminals on the injector plug, rather than probing one and getting the ground from elsewhere

[antus]

A common fault that keeps coming up on these forums is the fuel regulator failing and fuel going in to the engine through the reference pipe between regulator and manifold. If you havn't checked that first, it might be worth a look as well. Since you mentioned flashing of the test light in one of your tests I suspect that was a valid test and its confirmed the ECU injector drivers and the ECU reference pulses are OK.

[gazza]

I was checking the wire with the test light with the light wire to earth on the car and touching the wires on the plug and thats how i was getting live wires i done the same test on my vy the same way and the pulse wire did not lite up but it does on the vr.

[gazza]

replaced every sensor replaced fuel pressure regulator car fuel injectors have been done when the car is running it is running very rich spark plugs are black wet with fuel i don't know why it wont run if i go out the next day the car wont start plugs are full of fuel.

[antus]

you should measure 12v always on one of the pins of the injectors from that pin to negative / car body. The other pin goes to the computer to measure 12v battery to it and it should show no connection then flicker 12v just for a moment while cranking but you multimeter might struggle to see it, so any action is probably good. Its one way around or the other.

When did this start happening? Did you change anything on the car? Was it good then this just started happening one day? It sounds like there is something else here. Have you hooked it up to a PC and logged it and/or checked DTCs? Changed any other parts?

[vlad01]

As mentioned above, the ignition on and the engine not turning over/running. A test light over the 2 terminals of the plug, the light should definitely be OFF. If not, the ECU is most likely faulty or some shenanigans has been done to the wiring harness somewhere (bad LPG setup for eg.).

I find the best way to test injector pulse quick and dirty, is to get a wedge globe (globes used for the dash illumination), pry the leads down straight and they can plug straight into the injector plug so you don't nee to hold any multimeters or test lights and it goes straight across the 2 terminals just like the injector does.