1996 SHO Rose Mist - Code For 3 Misfires

Discussion in 'V8 - Maintenance & Troubleshooting' started by mrecoolgar, Jan 7, 2017.

  1. mrecoolgar

    mrecoolgar SHO NUP

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    I've delayed asking for help long enough.
    Car still runs but very badly and rough.
    Have codes: P0305: Cylinder 5 misfire, P0306: Cylinder 6 misfire, P0308: Cylinder 8 misfire and P1519: which I believe is a runner control stuck closed.
    Seems odd that I have 3 misfires at the same time.
    I was thinking maybe an electrical connector came apart partially or completely.
    The cams are welded and the car ran great, good power, smooth and quiet.
    Any help is appreciated.
    My new wife likes the car and I'd like to keep it for a while.
     
  2. sperold

    sperold Last to Know

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    Start moving coils around and see if misfires follow the move to the new location.

    There are circumstances where a number of coils can fail at the same time due to one issue.
     
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  3. SHOdded

    SHOdded SHO Member

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    All on the front bank, how rare is that! Congrats btw, Kevin!
     
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  4. GEN 3 SHO FAN

    GEN 3 SHO FAN SHO Member

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    1) It can be oil in spark plug wells.

    I have random misfires with no codes from front bank because I changed spark plug well gaskets (rubber rings) on rear bank only because of the heat there (and because they are 8$ each...) when I welded my cams 2 years ago. However some time after, age does it job and the front gaskets start to leak on plugs and coils after I opened the valve cover to weld the cams. This prob apeared very slowly but getting worst with time. Take me 2 summers to found what was going on with finally a P0305 code. (Cylinder #5 had many, #6 had a good quantity too, #7 had some traces and #8 had almost nothing)

    I must say that when I weld my cams, I changed the 2 valve cover gaskets but not the front plug well gaskets, maybe the tickness wasn't the same between old and new gasket. These gaskets with time became like hard plastic... Guys in shop here (you know already that probably) say me that oil is absorbed by the ceramic part of the plug and causing some internal ground. We cannot just clean a plug and put it in place again...

    2) Watch also a small (ground ?) wire starting from injector #5 (seems factory made) and going thru the runners and under the TB to the firewall on driver side. Some time after I rebolted my motor to weld it, watching if all was rebolted correctly, I saw this small wire sticked on EGR valve tube and badly toasted... I used a screwdriver to retreive from it and put a better protection it with electrical tape too. Not sure for what purpose it serves however...

    Just my 2 cents.
     
    Last edited: Jan 8, 2017
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  5. mrecoolgar

    mrecoolgar SHO NUP

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    Thank you sperold.
    Thank you SHOdded. And yes your old 95 ATX will live once again.
    Thank you GEN 3 SHO FAN.
     
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  6. SHOdded

    SHOdded SHO Member

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    Great to hear, Kevin :)
     
  7. GEN 3 SHO FAN

    GEN 3 SHO FAN SHO Member

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    Keep us informed maybe it's another thing...
     

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