Fuel Injector/Coil pack lines

[Justin]

Where, physically, do the wires for the coil packs run? Are all four wires going to the ECU? If so, great, I can find the pinouts.


Where, physically, do the wires for the injectors run? I know the fuel injector resistor is in line somewhere.....



Thanks

 

[jetjock]

The coil pack primary wires run to the igniter. The igniter wires run to the ECU through the engine harness.

The injector ground sides run to the ECU through the engine harness. The positive side runs to the resistor pack on the left fender and then to the ignition switch.

It's all in the schematic: http://tinyurl.com/53n9cs

 

[Justin]

The coil pack primary wires run to the igniter. The igniter wires run to the ECU through the engine harness.

The injector ground sides run to the ECU through the engine harness. The positive side runs to the resistor pack on the left fender and then to the ignition switch.

It's all in the schematic: http://tinyurl.com/53n9cs

Thank you.


The more and more thinking I'm doing of my problem, I seem to be focusing on the wiring to the fuel injector. ( No proof/evidence of this problem yet )

If I were to test #3 fuel injector plug, what would I want my meter to tell me, with ideal conditions?

I would THINK with my pos/neg lead in the two injector wires I would pulse on/off very fast 12 volts. Correct, or not so much so? I understand an auto ranging meter will have a hard time accomplishing this feat. I have a manual ranging blue point meter handy. I also have my two Flukes.

If I set my positive lead in the injector clip, on the wire that runs through the resistor, to the ignition then : with the ignition on, I should have a voltage based off 12 volts, dropped to whatever voltage the resistor brings it down to? (Negative lead on chassis ground)

If I have my positive lead in the injector clip, on the wire that runs to the ECU, I should just test continuity to the ECU plug, jah? jah?


If I'm making this too damn complicated and there's a better way to test for ideal injector signal at the injector harness please feel free to chime in with that too

 

[jetjock]

1) With the meter across the injector it would show a fast pulse *if* you had a meter good enough to see it. One with a frequency function. Most Flukes worthy of the name will.

2) With the meter referenced to ground you should indeed see +12 on the positive side of the injector. It won't be dropped much by the resistor. You'll also see +12 on the neg side as long as the ECU isn't grounding it. After all the injector coils are just long wires.

3) Continuity should exist between the neg side and the ECU. Another way would be to look for +12 at the ECU with the engine off due to what I said above.

4) A noid light is at one end of the spectrum for checking injector operation. A scope (or scope with a current probe) is at the other end. Choose what you have to work with.