Is there any way to tell what injector plug from the wiring harness matches up with what injector? For example, I'm not sure if I have the #2 and #4 injector wires switched, or #1 and #3, etc. I bought this engine and the wiring harness was completely disconnected so I'm not sure where the injector plugs were initially. This is an '86 305 motor from a T/A. Any help with this would be greatly appreciated.

Thanks!

 

UPDATE: Ok, I found a diagram that explained the fuel injectors a little better, I see that it is a batch firing system so it doesn't matter as long as the injectors are on the correct side of the engine. I do have another problem now, according to the wiring diagram one wire from each injector is supposed to go to the ECM pins D15 and D16 which ground the wires at the right time, while the other wire on each injector is supposed to go to one of the injector fuses. I checked continuity on the wires, and both wires on each injector go to the ECM pins, how is this possible? I can't figure out where the wires might be connected in such a way, do I need to just cut the wires and run my own to the injector fuses?

 

Howdy,

you are right, this is a batch fire system. Which means that all 8 injectors fire at the same time. And in that case, it doesn't what side is connected to what wire.

As for the continuity, there might have been a small measurement error. The injectors really are powered from the INJ fuses and grounded by the ECM. Did you perform the measurements with all injectors disconnected? Did you also pull both INJ fuses and disconnect the ECM? That is the only time when you will be able to successfully measure those 4 wires for continuity.

Hope this helps.
Lou

 

So is there an easy way to tell which cluster of injector plugs go to which side of the engine? cause i had the same problem, are the plugs marked? or just kinda guess according to how the plugs are arranged?

 

Unless someone has dismantled the harness; it is obvious when you lay wiring harness out on the engine which injector plugs go to which bank when you start connecting the other connectors to their relevent sensors

 

Like vetteoz said, it should be pretty easy to tell which side is which. If I remember correctly, the harness should have the bank of relays (fuel pump, MAF) on the driver's side, while there are a lot more connections on the harness that go to the passenger side of the engine bay.