Coil gone bad, again

[sportster2000]

The week before Mopar Nationals my coil went bad. Replaced it to find out that the alternator was bad as well. Replaced them and the voltage regulator. Now it appears that the new coil has gone bad, again. Any ideas as to what may be causing this?

 

[Adam]

Do you have electronic ignition, points, ballast resistor? Some coils can handle 3.0 ohms, some are .06

You need to match your coil with your system. Also, how is the coil mounted? It should be horizontal, or pointing down, so the internal oil can cool the business end.

Odd that the alternator and voltage regulator also went out... maybe something else causing the problem.

 

[sportster2000]

The first setup was from Mancini. Second coil was from O'riellys.

 

[Adam]

Some are designed to be used with resistors, most are not. So you could be getting too much voltage if not using a resistor, on a coil that needs one, or not enough voltage if using a resistor with a coil that doesn’t need one.

I think you need to use a meter on your coil and resistor connections and measure what you have; might be something else, but you can chase it down..

 

[Rob C]

If the coil is oil filled, shake it and you’ll hear the oil sloshing around, must be mounted standing up.
An epoxy coil, like stock, can be mounted as stock, laying down or sideways.
Failure to mount an oil filled coil standing up will result in the coil burning out. Not so with the epoxy coil.

And what the posts read above. Proper ohm ballast resistor, IF NEEDED! Double check electrical connects as loose connections cause issues. Make sure the engine has all three grounds tight & well grounded to bare metal. Battery to body, body to block, block to battery.
The same thing for the other electrical components.

 

[i_taz]

If the coil is oil filled, shake it and you’ll hear the oil sloshing around, must be mounted standing up.
An epoxy coil, like stock, can be mounted as stock, laying down or sideways.
Failure to mount an oil filled coil standing up will result in the coil burning out. Not so with the epoxy coil.

And what the posts read above. Proper ohm ballast resistor, IF NEEDED! Double check electrical connects as loose connections cause issues. Make sure the engine has all three grounds tight & well grounded to bare metal. Battery to body, body to block, block to battery.
The same thing for the other electrical components.

Great...just bought a FAST PS20...oil filled but was told you lay it down

 

[Rob C]

Who told you that?

 

[i_taz]

That's how they are and someone on Summitracing asked the question and were told 'of course' you can. My factory sounds like it's oil filled but doesn't slosh around like this FAST does....guess it's going back

 

[Rob C]

Double check with the actual manufacturer.

 

[AUSTA]

You could use a MSD epoxied oil free coil if position is a problem.

 

[i_taz]

F.A.S.T. said no problem... It's strange how much air is in it though. My NLA Mopar coil certainly seems like it's oil but you really have to shake it to feel it. I happen to have a MSD from my MSD 6 from an old boat. I'm really trying to improve starting much like that boat motor. That was a 318 with a Holley 4160 and the MSD ... 2 pumps of the throttle no matter how long it sat for months at a time, it fired right up with a direct drive marine starter too. I don't think the motor turned over 2 times even with the choke wired wide open....I primarily contributed it to the ignition but I'm trying to keep my car stockish....

 

[moparlee]

F.A.S.T. said no problem... It's strange how much air is in it though. My NLA Mopar coil certainly seems like it's oil but you really have to shake it to feel it. I happen to have a MSD from my MSD 6 from an old boat. I'm really trying to improve starting much like that boat motor. That was a 318 with a Holley 4160 and the MSD ... 2 pumps of the throttle no matter how long it sat for months at a time, it fired right up with a direct drive marine starter too. I don't think the motor turned over 2 times even with the choke wired wide open....I primarily contributed it to the ignition but I'm trying to keep my car stockish....

But was that with today's crappy gas, or were you running rec gas in your boat?

 

[i_taz]

Just pump gas from 8 yrs ago or so... The stars just aligned...I know I'm going regret getting rid of that old gnarly carb, I think that had something to do with it too but back to the coils, I did put the gnarly old MSD coil on and seat of the pants is telling me something positive. Now time to unbox the PS20 again and see if that's got anything for me...

 

[sportster2000]

I have to coil laying on its side. It was oil filled. It is on a big block. Going to order an epoxy filled one as a back up to the new one.