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diagnostics help needed

Discussion in '348/355' started by dontknownuttin, Jun 7, 2014.

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  1. dontknownuttin

    dontknownuttin Karting

    Mar 21, 2014
    133
    Forest Lake, MN USA
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    Jonathan
    #1 dontknownuttin, Jun 7, 2014
    I recently wrapped up my 30k service and everything is back together. But...... It starts up easily, but it after fires (backfires) a fair amount only at idle, giving it throttle yields little power, and driving it is as slow as economy car. I just went through and cleaned up the plug wire ends and verified they are in the correct order, though I have not been able to find a single document that 100% verifies which one goes to which. The way I have it now, 1-4 goes to 1-4 on the coil, and 5-8 goes to 1-4 with each -4. That is, 5 goes to 1, 6 goes to 2, 7-3 and 8-4.

    Any other things to look for?
     
  2. fatbillybob

    fatbillybob Two Time F1 World Champ
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    Aug 10, 2002
    29,260
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    #2 fatbillybob, Jun 7, 2014
    Didn't you take the heads off this car? If so did you verify compression and leakdown. Basics first.
     
  3. dontknownuttin

    dontknownuttin Karting

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    #3 dontknownuttin, Jun 7, 2014
    Did not take heads off.
     
  4. tr512

    tr512 Formula 3

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    #4 tr512, Jun 7, 2014
    Did you do your belts? and if so did you make sure your cams are timed right
     
  5. tbakowsky

    tbakowsky Two Time F1 World Champ
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    #5 tbakowsky, Jun 7, 2014
    +1
     
  6. dontknownuttin

    dontknownuttin Karting

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    #6 dontknownuttin, Jun 7, 2014
    I did do the belts. I marked each pulley and tooth it was on, and triple verified the new one being on exact same teeth. That said, perhaps I need to pull the valve covers off to re-verify. It's cylinder 1 at TDC and then the mark on each cam should be lined up with the mark near the gear on the inside, correct?
     
  7. dontknownuttin

    dontknownuttin Karting

    Mar 21, 2014
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    #7 dontknownuttin, Jun 7, 2014
    Also, if the timing was off by at least one full tooth, wouldn't it cause a CEL?
     
  8. tr512

    tr512 Formula 3

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    #8 tr512, Jun 7, 2014
    This is not a smart ass remark.But i have never timed the cams wrong so i don't know if a cel would come on.
     
  9. plugzit

    plugzit F1 Veteran
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    #9 plugzit, Jun 7, 2014
    No.
    You can quick check timing, assuming you didn't move the gears on the cams, thru the slots in the timing cover with the engine at TDC compression. There's a timing mark on the gears that corresponds with the slots.
    Also, there won't be any popping when off 1 tooth.
    Recheck firing order on 5-8 side clockwise from plug 6-7-8-5
     
  10. dontknownuttin

    dontknownuttin Karting

    Mar 21, 2014
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    #10 dontknownuttin, Jun 7, 2014
    I did not move the gears on the cams. The slots are on the back side?
     
  11. dontknownuttin

    dontknownuttin Karting

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    #11 dontknownuttin, Jun 7, 2014
    Ok, I found the slots. Will have to get TDC tomorrow and verify. I assume it is TDC for #1?
     
  12. dontknownuttin

    dontknownuttin Karting

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    #12 dontknownuttin, Jun 7, 2014
    This is a 348
     
  13. plugzit

    plugzit F1 Veteran
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    #13 plugzit, Jun 7, 2014
    Yes.
    Also, don't forget F numbers their cylinders 5-8 starting from rear. Makes it easy to confuse 6 & 7.
     
  14. dontknownuttin

    dontknownuttin Karting

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    #14 dontknownuttin, Jun 7, 2014
    Does anyone have a diagram of plug wires 5-8? My coil is not labeled, and thought I think it is right, it is only an educated guess.
     
  15. plugzit

    plugzit F1 Veteran
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    #15 plugzit, Jun 7, 2014
    Looking at the four plugwire terminals, begin clockwise from the plug. 6-7-8-5
     
  16. dontknownuttin

    dontknownuttin Karting

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    #16 dontknownuttin, Jun 7, 2014
    Begin one which one? It us labeled 1 through 4 just like the other side, but upside-down because it's on the other side.
     
  17. bosshog8

    bosshog8 Formula Junior

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    #17 bosshog8, Jun 7, 2014
    Standing on the passenger side and looking at the coil the sequence starts from the top left and continues like above.
     
  18. plugzit

    plugzit F1 Veteran
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    #18 plugzit, Jun 8, 2014
    Look directly at the four terminals. Straight on. Ignore the yellow label. You cant' see it anyway when you look straight at the four. Look straight on at the four terminals. See the plug sticking out that connects the wire harness? Begin there. Go clockwise to the first plugwire terminal. That's six. The next one clockwise is seven. Then eight. Then five. You're now back at the harness plug. Done.
     
  19. dontknownuttin

    dontknownuttin Karting

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    #19 dontknownuttin, Jun 8, 2014
    Bingo!!!!! Sooooo smoothly running now. :D Thanks!
     
  20. ernie

    ernie Two Time F1 World Champ
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    #20 ernie, Jun 8, 2014
    This link has the stickers off my coils showing how the spark plug wires get plugged into the coils. http://www.ferrarichat.com/forum/140204171-post7.html
     
  21. dontknownuttin

    dontknownuttin Karting

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    #21 dontknownuttin, Jun 8, 2014
    My 5-8 has no sticker, hence the guessing. Thanks so much for the info! Been driving it for the first time since I got it (except for the short first test ride). SOOOOO happy now!
     

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