Hey, I was working on the harness today when I came across a few roadblocks...

First, I had to cut two of the injector connectors off and I figured it would not be a big issue, until I came around to trying to pair them out. The FSM I am using states that the wires are Light Green/(Color) paired with a Black wire, but the Black wire from EM-03 (the smaller yellow ECM Connector) runs to a large Resistor Pack and then off shoots four Brown/(color) wires that seem to be the grounds. The problem is that thise Resistor Pack is obviously OEM but not in the FSM diagrams and I am not sure which LG wire and BR wire combo makes which injector...

Second is there is a large Grey wire that comes from a black wire splice... the issue is that I don't see where this grey wire could go and the diagram doesn't mention it as far as I see.

 

No one has any ideas?

 

the resistor pack is 86-87.5, it goes on the ground side of the injectors.

or its like power -> injector -> resistor -> ecu -> ground

 

Damn it... this is why I wish the FSM I was using wasn't an '88

So which pairings make up the injectors? Because I have four Light Green/(Colored Stripe) and four Brown/(colored stripe) and am not sure which ground goes where.

and what about the Grey Wire?

 

Does anyone know where I can get a 1986-1987.5 FSM Wiring Diagram?

 

Not sure if anyone cares or not... but if you are curious...

I figured out the injector wires, it doesn't matter which light green & brown wiring pairing you do since the Resistor Pack has only one Ground wire going INTO it and 4 Brown wires coming out of it. Which means that the 4 Light Green Wires that come from the ECM are the control wires and are the ones that you should be worried about mixing up.

As of this post I still have not figured out what the hell that grey wire goes to..

 

i was gonna say it doesnt sound factory, but if its paired up with the injector, it might be the 02 sensor? there is a signal wire, and a ground sheath...

 

Wonderful! This was the exact thing I was going to post on next too!

The outside is a ground Sheath that connects to Pin 3G on Connector EM-03 and the center is a Black Wire (must be signal) connected to Pin 2D off of Connector EM-31... Or it may be reverse where the outside is the signal and the center is the ground... I'm not a 100% sure because the diagram seems rather strange at circuit...

 

The O2 wire is one of the very few shielded wires in the entire harness. On the FCs, and SEs, the O2 sensor only comes into play during steady state cruising to modify AFRs for fuel mileage and emmissions. You will notice little to no difference if it's non-op unless most of your driving is highway on cruise control. If you could post a pic of the connector on that wire, I could tell you if it's the O2 wire or not. It should have a braided wire sheath under the outer covering similiar to coax cable but w/o the aluminum foil wrapper.

If you can't find the wiring diagram you need, I do have an 87 hardcopy of the FSM.

The resistor pack is for the low impedence injectors. After mid 87 all injectors were changed to high inpedence and the ballast resistor was no longer needed.

 

Thanks Trochoid, the problem is that the connector for the wire is missing, but it is exactly like you describe so I am safe to say its the O2 Sensor.