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Cylinder 3 misfire (04 SVT Focus)

Discussion in 'SVT Focus' started by 96S/Cobra, Oct 17, 2020.

  1. 96S/Cobra

    96S/Cobra Member Established Member

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    I know this forum is really quiet these days, but I'm hoping someone out there will see this and can maybe give me some direction on where to go from here.

    My dd 04 SVT Focus keeps having a cylinder 3 misfire. It is random on when it occurs, and will typically go away within 5-10 minutes of driving. Sometimes it happens upon start up, then will go away after a bit. Sometimes the car starts up perfectly, and then once driving the misfire will occur for awhile, but will ultimately go away.

    I've replaced all spark plugs and wires with Motorcraft parts. I've replaced the cylinder 3 fuel injector. I've replaced the MAF sensor. The fuel filter has approximately 6,000 miles on it. *edit* I've also replaced the coil with a new Motorcraft coil.

    I ended up taking it to a repair shop that I trust, and they are stumped. They checked fuel pressure as well as did a compression test and all returned normal results. The only thing they wonder is if it could be something internal in the engine/head as when the car is sitting there running perfect they would use their mechanics stethoscope to listen to every cylinder. They did say that when the car is sitting there and begins to misfire, cylinder 3 does have a different sound. Now is this due to the shear fact that this particular cylinder is not firing, thus the sound would be different than a normal firing cylinder? I'm not sure.

    Do I need a new head? (I don't know where to get one anyways). Could it be something else intermittently going in and out (a sensor, wiring/wiring connection)?

    Any and all help on where I could go from here would be greatly appreciated. If I can't get this issue figured out, I will have a sonic blue 04 SVT Focus for sale or will part it out for anyone who is interested.
     
    Last edited: Oct 17, 2020
  2. DSG2003Mach1

    DSG2003Mach1 Well-Known Member Premium Member Established Member

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    These have plug wires and not coils? Have you check the electrical connector to the injector and coil (if cop?) I had a Coil connector with a broken tab that gave me a random misfire on my lightning, took a bit to figure that one out
     
  3. 03cobra#694

    03cobra#694 I Have LL’s Hammer Staff Member Super Moderator

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    Pretty sure it's coil on plug. My money is on a coil. My wives Escape would start missing randomly and I had to wait for it to throw a code before I knew which one to change. It's the 3rd one I've done on it.
     
  4. 96S/Cobra

    96S/Cobra Member Established Member

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    Sorry guys, I feel like an idiot not mentioning in my original post about the coil. It is not coil on plug, it is a standard coil that all plug wires run and plug into. And yes, this has also been replaced with a brand new Motorcraft coil. I will re-check the plug on the injector as well as the plug on the coil, but I'm very certain neither of them have any broken tabs on the connector. But I guess the possibility exists that somewhere the wiring for cylinder 3 is making a good connection "most" of the time...but then at some point it loses connection and then begins to misfire. This has been a real headache that has been plaguing this car for months and I am at my wits end with it. Thanks for the reply's though.
     
  5. DSG2003Mach1

    DSG2003Mach1 Well-Known Member Premium Member Established Member

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    I’d replace that wire again if it just means swapping from a running car as a test, ew doesn’t mean it’s good
     
  6. 03cobra#694

    03cobra#694 I Have LL’s Hammer Staff Member Super Moderator

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    Have you pulled the plugs and checked the gap again?
     
  7. 96S/Cobra

    96S/Cobra Member Established Member

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    I have the previous set of plug wires that I took off the car from when I swapped the new Motorcraft wires onto it. I will take the old cylinder 4 wire and swap it onto the car to try that out. I have not pulled the plugs to check the gap, but I will. Thanks again guys for tossing ideas my way. Give me a few days to get to it and I will update this thread.
     
  8. hotcobra03

    hotcobra03 Well-Known Member Established Member

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    Chilton Library

    Scroll down for link to enter

    full manual is in here
    Tests for codes section is very helpful now
     
  9. hotcobra03

    hotcobra03 Well-Known Member Established Member

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    What codes are you getting when scanning? Key on engine off

    does scanner do engine running tests?
    Key on engine running test may give codes that aren’t in key on engine off
     

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