so i read the thread a few weeks ago re regapping plugs w/ hei. when i got home i regapped the plugs in my 327 to .045 and now have developed skip underload. i am having an old fart moment. what do i need to do with timing and regapped plugs. at first hought it was crappy gas from sitting too long but at this point? thanx larry
my 1st thought would be if thats all you changed, go back to your initial gap and see if the problem goes away...
How long has it been sitting with that gas? If you are already running lean, opening up the gap MAY make it skip but unlikely. If the gas is over 3 months old swap it. How much timing are you running? peace
I always use the .045 for electronic and .035 for point rule. May be the carb or something in the distributor?
If you regapped old plugs your "Spark" could now be traveling up the insulator around the electrode due to carbon, oil build up etc. and causing a stumble under load. By increasing the gap you have now increase the resistance for your spark to make the jump across the gap under a load. If plugs are new check other areas like wires, cap, rotor etc.
check the easy stuff first.Once i didn't put a wire on a plug all the way and it didn't miss all the time but it would skip every so often when idoling.Stupid but hey it happends
Both my cars have HEI, and when I checked, both had .035 gap. Cleaned plugs and reset gap to .045 and noticed an immediate smoother idle. And better pull under acceleration. A "skip" won't be caused by plug gap. As has been mentioned, I would look for a bad wire, bad plug, or bad connection.
Toymaker has it right, I think the resistance has increased causing spark leak. Even though you notice it under load, try running the car with the hood open in a very dark garage. Look for spark jumping. If you have an automatic, have someone brake torque it in gear to create a load. I've run HEI plug gaps at .060, some have run at .080 with a CD box. You are running your HEI at 12 volts, right?
Used HEI stock GM? .045 is too much, go back to about .040 and drive it again. You time it the same way you would if you had points.
Some wild answers here for sure. Plug gap goes with combustion chamber and engine design NOT the ignition system. A 327 needs .035 not the .045, the 045 just askes for increased energy thats not needed with the combustion design. Longer burn times were mandated by lean air fuel ratios, most hot rods are not lean for sure...
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