S8 Injector wiring

[tarmac terror]

OK, I KNOW some folks will give it the "if you have to ask you shouldn't be doing it" thing. Before I go further I used to be a mechanic many moons ago but confess vehicle electrics were never my strong point hence the post.

The scenario is that I will be installing an S8 into my Skyline R32GTR. I will be using Injector Dynamic ID1000's and am looking to get rid of the original wiring and make something bespoke and a bit more rugged. My dilemma comes from the fact that I have done some research on the net into wiring and I see that some injectors are given a +ve input on 1 pin with the negative being connected to ECU. The injector fires in this case by the fact that the ECU grounds the circuit.
Most of the systems I have seen do it the other way by having a pin grounded and the feed supplied directly by the ECU injector driver such as in the case below....



Now, all I am looking for is clarification that THIS IS the correct way to wire them up? I'm presuming it is but don't want to go and make a loom only to find I have conceptualised it completely incorrectly

Many thanks in advance,
TT

[pavlo]

NO!

The injectors are fed with +12v from a fused supply, and are grounded by the ECU to turn them on.

This is similar to how most outputs of the ECu are used, including ones for relays, solenoids and actuators.

Please read the manual and save yourself some hassle, much of the S6 stuff applies the ignition is the main difference.

[tarmac terror]

OK, so more like this....??



TT

[pavlo]

Yes that's more like it, sorry for the initially short reply I was off out the door.

Your +12v supply for the engine will want to be ignition switched, and you can also use the same feed, perhaps individually fused if you want (so switch is unfused, or two 5amp feeds fed from a general 30amp fuse). That way you can have say a master switch on, that leaves the ECU powered for setup and looking at logs, but the engine will only run when you switch the power on for the injectors and coils.

Some setups suggest using the fuel pump output to trigger the +12v for the injectors, this is a pain and I wouldn't recommend it. If you want to check anything that relies on the fuel pump running then you have to manually switch it on, and you might want to check lots of things without the pump running.