Coil arcing and unable to idle below 750 rpm

[nateo]

Hello again. ok, so I have no crazy noise coming from engine, it actually sounds pretty smooth. However I can't get it to stay running below 750 rpm it stalls. While trying to adjust timing I've been getting tiny little shocks when I turn the distributor. Today I seem it arc from center post to neg on coil. I have recently replaced cap & button. I have also recently replaced knock sensor. I have the sensor itself grounded to exhaust block and to make sure I also ran a new wire from post on bottom of distributor to ground on battery. I don't see any cracks in coil. Should I try replacing coil and or wires or might I have something wired incorrectly?

 

[stonyloam]

electricity finds the path of least resistance to ground. A spark from the center wire is finding LESS resistance jumping to the ground than in the ignition system. Could be dirt on the coil is allowing a "short", the insulation on the wires may be breaking down and "leaking", or you may have some high resistance in the wires. Try cleaning the coil to remove any dirt. Then they his: start the engine in the dark and look for sparks arching off of the wires, take a spray bottle and spray a little water on the wires to see if you get arching. If you see ANY sparks, replace the wires.

 

[gm280]

I once had similar issues with a distributor cap. Seems the cheap cap I bought was plastic instead of quality resin material. It did make a huge difference... JMHO!

 

[nateo]

I didn't use locktight on the new rotor, any chance that could make any difference?

 

[nateo]

just looked at manual, it said I'm supposed to bend tab on top of rotor to be 1/4" from rotor and tang. However the picture looks slightly different then mine. Mine has a little plastic post on top of plastic rotor. Should I be 1/4" from tiny plastic post or rotor? Does it really even matter?

 

[alldodge]

While trying to adjust timing I've been getting tiny little shocks when I turn the distributor. Today I seem it arc from center post to neg on coil.

I think you need a new set of wires

 

[nateo]

I think you need a new set of wires

I like this answer because its easy to do will pickup some tonight.

 

[flipbro]

Bad wires for sure or one wire is off..

 

[Bt Doctur]

if the arc is consistant,it could be a dead spark plug

 

[nateo]

Going to replace coil and wires then all jgnition stuff will be new. Mercury all the way for both of those or can i get aftermarket stuff at auto store?

 

[Eric 3.7LX Alpha 1]

I am running Mallory Marine wires, 8 mm I think. Real nice set.