Strange misfire issue
07-24-12, 07:14 AM
#4
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I'm sorry but none of these plugs look "normally used" to me.
Plug #1 seems to have a bridge across the gap, probably made of a anti-seize grease. Plug #2 appears to have a silver band on the insulator, which may also be anti-seize, shorting out the points. Hence these two are not firing.
Plug #6 and #4 are simply oily. You may have leaky valve seals there that lets in the oil.
Plugs #3 and #5 are sooty. Either the driving habits were unhealthy, or the mixture too rich, or the plugs are too cold.
Normal used plugs will be grayish in color without signs of soot and wetness.
I'd say, replace all six with proper plugs and try again. do not bathe them in anti-seize lubricant. If they still misfire, check the coils.
Plug #1 seems to have a bridge across the gap, probably made of a anti-seize grease. Plug #2 appears to have a silver band on the insulator, which may also be anti-seize, shorting out the points. Hence these two are not firing.
Plug #6 and #4 are simply oily. You may have leaky valve seals there that lets in the oil.
Plugs #3 and #5 are sooty. Either the driving habits were unhealthy, or the mixture too rich, or the plugs are too cold.
Normal used plugs will be grayish in color without signs of soot and wetness.
I'd say, replace all six with proper plugs and try again. do not bathe them in anti-seize lubricant. If they still misfire, check the coils.
07-24-12, 07:45 PM
#6
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If there is no sign of combustion then it is possible that you have injector problems on these two cylinders. Get a stethoscope and on the running engine listen to each injector clicking. Or, in a pinch, pull harnesses of injectors one at a time. If you pull a good one, misfire increases; if you pull a bad one there will be no change.
07-25-12, 04:52 AM
#7
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Spark or no spark is very easy to detect ..
Just lay the connected spark plug on the valve cover. If you do this is dark surroundings, you will see the spark.
Granted the above procedure does not check timing, but is a very simple test.
RX also throws a CEL and gives you the code as to which cylinder is misfiring. For ease move the suspect coils/plugs to the even number cylinders (towards the radiator) and confirmed good ones to the back (odd number).
Salim
Just lay the connected spark plug on the valve cover. If you do this is dark surroundings, you will see the spark.
Granted the above procedure does not check timing, but is a very simple test.
RX also throws a CEL and gives you the code as to which cylinder is misfiring. For ease move the suspect coils/plugs to the even number cylinders (towards the radiator) and confirmed good ones to the back (odd number).
Salim
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