[BRUTEL 1]

Working on a 71 chevelle with a 454. Has a HEI dist. After reving the car up it missfires. I checked with a spark tester and when it missfires it sparts 5-6 times then no spark 1-2 times then sparks again. My thought is it has a coil going bad. The module is possable but when they have gone bad on me they loose all spark. No missfire like this is doing.

Any other ideas?

Thanks Rich

 

[GuysMonteSS]

If the distributor drive gear is worn it could possibly cause the problems you are describing.Or if the bushings in the distributor housing are worn out it could cause this also.
Guy

 

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Don't have specifics on the misfire, but I had a spark issue last week that caused a no start. Did get spark when testing but I guess it was just weak spark. Changed coil, rotor, and module it and fixed the problem. By the looks of the parts I replaced, the coil and rotor looked brand new but the module looked pretty old (I had just bought the car). My guess is that it was a bad module causing weak spark.

Since the parts are not expensive, I would start replacing those parts in the distributor and see if it fixes it.

 

[Tom Mobley]

Rich, use a vacuum pump, one of the hand held deals, to activate the vacuum advance at idle, see if you get the problem.

If you do, use a pair of needle nose pliers to pull on the little wires where they come out of the pick-up coil in the HEI. Sometimes these get old and break inside the insulation. Pull on the wires gently, if one of them is more like a rubber band than a copper wire you've found the problem.

 

[BRUTEL 1]

I replaced the module, coil, cap and rotor the problem is gone

 

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I replaced the module, coil, cap and rotor the problem is gone

:hurray: