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Tonight I removed all 4 connectors from the ECM, removed EFI relay and EFI fuse. I still get +12VDC on the injector #1 pin. I now see what you're talking about the clock being connected to injectors #1. There is a common node in the circuit.
Tomorrow night I will disconnect the clock from the circuit. It appears "IL1" is a connector behind the glove box that will disengage injector #1.
I also ran the motor with my scanner hooked up and verified a code P0301 "Cylinder 1 Misfire Detected".
One note, does your schematic show the clock Pin 7 (TAU) connecting to the injector then out to TAUB and also (IG) 15A IGN? The (IG) Source is from the ignition switch. I may have a bad ignition switch.
I will let you know how it goes tomorrow night. Thank you again, I really appreciate it.
Originally Posted by toyomoho
The injectors always have +12V power when the EFI relay is closed. The ECU then opens and closes the return wire from the injector to complete the circuit.
The wiring diagram shows a tap off between the No 1 injector return wire and the ECU its connected to (blue wire). This tap goes to the clock.
Unlike a typically cars clocks this clock has about 15 wire connections to it. Guessing the injector connection provides input as to if the injector is operating for auto trans equipped cars. The stick shift trans equipped cars have a wire going to the clock from the speedometer.
The issue could be bad wiring, an ECU problem or something with the clock internal circuits.
Might track down the wiring at the ECU. Then disconnect the wire from No 1 injector at the ECU plug. If the injector stops working then the issue appears to be the ECU. If it keeps working then the issue is wiring between ECU or clock.
Does your schematic show the clock Pin 7 (TAU) connecting to the injector then out to TAUB and also (IG) 15A IGN? The (IG) Source is from the ignition switch.
Yes.
Look at the wiring diagram for the injectors. This has the blue wire from the injector being tapped off to go to the clock.
Code can be for the injector issue.
Can you disconnect the wiring going to the clock and determine if the injector stops buzzing?
When I get home from work tomorrow that will be my first task. I’ll disconnect connector “IL1” and see if the buzzing stops. I’ll report the results here.
Originally Posted by toyomoho
Does your schematic show the clock Pin 7 (TAU) connecting to the injector then out to TAUB and also (IG) 15A IGN? The (IG) Source is from the ignition switch.
Yes.
Look at the wiring diagram for the injectors. This has the blue wire from the injector being tapped off to go to the clock.
Code can be for the injector issue.
Can you disconnect the wiring going to the clock and determine if the injector stops buzzing?
it’s been awhile since I’ve had a chance to report the latest. I removed connections to Injector # 1, the ECM, all other connectors. It turns out voltage is being fed into Injector 1 if I move the bundle of wires near the intake manifold. I can make the voltage appear or go away depending on the pressure applied or position of the wires.
Ii think something is shorting between wires within the bundle.
Question:
Can the engine harness be removed or at least enough to check the wires without removing the intake manifold? I don’t want to completely take out the harness, just enough to inspect the wiring feeding into the intake manifold area.
Voltage feed into injector. Remember the injector always has 12V power via the IGN fuse when ign key is on. The ECU just grounds the return wire to complete the circuit.
The injector and ign wiring runs to the drivers side of engine. Then splits between the drivers side fuse box and running back along the front of the engine.
Is this ign on and injector then running? There is supposed to be nothing in the area but injector and ign wiring.
The intermittent voltage is present without a key in the ignition. It will appear if I “wiggle” the bundle of wires.
I wasn’t sure if the bundle of wires went along the under side of the intake manifold. I disconnected the fuel injectors and ignition coils. This provided some slack but something else is holding the harness down. I also removed the 2 harness mounting clip bolts.
I’ll check the ECM cabling going into the rear of the glovebox to see if that needs to freed up.
Thank you for your feedback. It’s much appreciated.
The “wiggle” area is located right before the bundle of wires goes under the intake manifold. If I remove the ALT-S fuse (5 amp) the voltage caused by wiggling the wires no longer appears.
Perhaps there is a short somewhere between ALT-S and other wires?
Originally Posted by toyomoho
Where is the wiggle area located?
Try removing the ALT-S fuse to the alternator as this wire is always hot.
04-15-2019, 11:05 PM
