Fuel Injector not getting voltage

Discussion in 'Modifications And Maintenance' started by OneGlanceMan, Oct 15, 2020.

  1. OneGlanceMan
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    OneGlanceMan Member

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    Cylinder #3 Fuel injector isn't getting any voltage. Had the plug cut off, exposed new wires, and tested the wires. Still not getting any voltage. Any idea what's the cause of this?
     
  2. euro
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    euro Well-Known Member

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    Wire break down the harness possibly
     
  3. OneGlanceMan
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    There's somewhat a voltage, but not a stable steady number voltage. Pulled out the wire harness and checked the wires thoroughly. Nothing wrong. Ecu wire harness to brown plug in engine bay also checks out fine. Wire loop under the driver front fender checks out fine too. Possibly the ECU?
     
  4. euro
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    euro Well-Known Member

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    What do you mean by somewhat stable voltage?
     
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  5. Chux
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    Chux Well-Known Member

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    Generally, all the injectors get power from the same source, so it is mostly likely a wiring break.


    Can't really give any more information without knowing the situation. Year, Make (Subaru?), Model, Engine, Maintenance/modification history?
     
  6. OneGlanceMan
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    All my other injectors voltage were getting a reading of 2.0 and was staying on that number on a multimeter. Injector #3 volt number was jumping around not staying at a number between 0.7 to 1.6 on the multimeter using 200m. That's what I meant.
     
  7. OneGlanceMan
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    2002 Subaru Impreza WRX
    Engine: JDM EJ206
    Modifications: 565cc Pink Fuel Injectors, downpipe, exhaust, steamspeed ebcs, aps 65mm air intake w/ k&n air intake filter.
    Yes, I am I running a base map for this setup and waiting to get tuned.
    No pulse on fuel injector #3 at all including when I rev. Gonna be replacing the ecu to see what'll happen.
     
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  8. euro
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    euro Well-Known Member

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    Still sounds like a potential broken or weakened wire. Ecu maybe but i would expect it to be all or nothing if it was an ecu.
     
  9. Chux
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    Chux Well-Known Member

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    Excellent, thanks

    2.0...Volts?

    The power side of all 4 injectors comes right from the main relay. Should get basically battery voltage (some drop for the wiring, but minimal). Same leg of the main relay that supplies power to the MAF, wastegate solenoid, idle solenoid, and purge solenoid. ECU has nothing to do with it, beyond activating the relay.
     
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  10. OneGlanceMan
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    So after doing a little bit more digging, I found that its not the ecu because I replaced it with a spare one. The positive wire (red wire) is getting good voltage and the noid light lights up when I used a different grounding (intake manifold), but when I use the negative wire (white wire) I get nothing and no light on the noid light.
     

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  11. Chux
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    Chux Well-Known Member

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    If the noid light doesn't flash when running/cranking. And you've got 12v going to it. You have a break in the wire between the injector and ECU. There are 2 connectors between there, so I'd Ohm each section and see where the break is (and, of course, inspect those connectors).
     
  12. OneGlanceMan
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    Forgot to reply a few days ago. I found the problem/issue. Previous owner actually had broke the wires, soldered the wires together, and used a heat shrink tube. I did test it for continuity and it was staying at I. It was located near the ECU. I've been quite busy the past few days after I found the problem, so I hadn't have time to fix it yet. I'll let you know if everything works after I fix it!
     
  13. OneGlanceMan
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    Got it fixed yesterday. I got the wires crimped, used heat shrink tube, and taped it up with electrical tape (Scotch Super 33+). It was weird and a wtf thing on how I got it to work. Wires wouldn't work until I used a 18g wire between the exposed wires.
     
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