Can you feel a SINGLE missed ignition? | FerrariChat
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Can you feel a SINGLE missed ignition?

Discussion in 'Technical Q&A' started by UroTrash, Jan 4, 2005.

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  1. UroTrash

    UroTrash Four Time F1 World Champ
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    Jan 20, 2004
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    Clifford Gunboat
    #1 UroTrash, Jan 4, 2005
    OK heres a little question for all the smart guys here.

    Say you have a car engine running a fairly high RPM, say 6,000 RPM and it starts missing.

    Can the missing be accounted for by SINGLE failures in a SINGLE cylinder? In other words, when you feel a skip, is it only one missed ignition of is it maybe 20 or 30 in a row(in 1/5 or 1/3 a second)?

    It seems odd that you could detect a single missed ignition when you have 799 other during that same second. (6000RPM is 100RPS x 8 cylinders - 1 miss).

    Can a miss be as likely a lack of spark as a lack of gas? Which is more common reason for a skip?

    If its a lack of spark, would the next ignition not be a "big bang" like throwing a double charge in hand-loading ammunition? Or does the extra gas go out the exhaust valve for a backfire a split sec later?

    Thanks.
     
  2. Rifledriver

    Rifledriver Three Time F1 World Champ

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    Brian Crall
    #2 Rifledriver, Jan 4, 2005
    Is this just an intellectual exercise or is there something wrong with your car?
     
  3. Spasso

    Spasso F1 World Champ

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    Han Solo
    #3 Spasso, Jan 4, 2005
    If it is a continuous miss for a second or two I can tell. More so on an "odd fire" American V8

    Usually spark but it can occur on a "port injected" engine with a faulty injector.

    With a continuous miss for a long period of time the fuel charge goes out the exhaust valve and can sometimes start fires in a hot catalytic converter. It also loads up the cylinder, soaks the spark plug and washes the cylinder down causing excessive wear.

    I have seen where a momentary miss can cause a backfire but not every time. One car I had in particular would backfire LOUDLY on command by turning the ignition switch off for a half a second then back on while the gas pedal was to the floor.

    The cops LOVED that one.....................
     
  4. UroTrash

    UroTrash Four Time F1 World Champ
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    Clifford Gunboat
    #4 UroTrash, Jan 4, 2005
    Purely curiosity.

    So can you feel a single miss or is it always a series needed to be felt?
     
  5. Spasso

    Spasso F1 World Champ

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    #5 Spasso, Jan 4, 2005
    A series.
     
  6. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
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    #6 Rifledriver, Jan 4, 2005
    I do not believe you can if it is a single event at high RPM, at least on multi cyl engines. On a twin, maybe yes. The best example of it I can think of is on the fuel dragsters at a night race. You can clearly see the eight exhaust stacks and their plume. You will see an ocasional miss as indicated by the color or lack of plume but will never hear it. As you say in that short period I can not imagine feeling it either. I think that in most cases that we are aware of, the situation that exists to cause a miss lasts long enough to cause multiple misses. At idle or low RPM, no question you can hear each one in some cases.
     

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