Melted coil power connector

[c2xejk]

How can the coil be saturated any faster without raising the voltage? The stock setup sends in battery voltage. How is the capacitor saturating it faster?

Regardless, if you are firing the plugs more times/cylinder event, you are pumping more current in. More current-> more heat...

[kermit]

V=I*R. Voltage could stay the same if current is increasing and there is less resistance in the coil. You need bigger wires that can handle more current.

[lookin]

Quote:

Originally Posted by c2xejk The result is you are melting the wires because they are carrying more current than they are rated for...

I really appreciate you getting involved and helping Ed. Just to be clear though. The harness wires, leading to the connector, are not melting. They aren't even heating up that I have noticed.

The female pin contacts inside the harness coil connector, that the male coil pins slide into, are what is heating up. Then they very slowly melt that plastic harness plug they are inside of.

(A)
|| <- the two male pins on the coil itself

(B)
UU < the two female harness plug pin contacts


So my theory is this.

The female pin contacts were a bit sloppy, leaving some airspace between them and the male coil pins, which allowed some arcing to take place and generate heat.

This heat generation, slowly increases over time, because carbon builds up at the arcing points and decreases current resistance. The lowered resistance then increases the arcing, that degraded the metal pin contact, part of which fell out of the connector upon my inspection of it..

Is any of that right? Or have I made some wrong assumptions here?

On Edit: ( Clarified the stuff in red, and added forgotten detail about part of the metal contact falling out)

Maybe I can compensate for that, by getting a new harness coil connector and bending the female pin contacts together a bit more, so they fit tighter on the male coil pins, and the arcing will not happen anymore?

Man I am way outa my league here.

Please help.

[lookin]

Quote:

Originally Posted by Reaper1 While I agree with the theory stated above, I don't see this melting the connector because we are only talking probably a maximum of 300 milliamps at 12V. The capacitor does not step up voltage, that's not its job. It only stores energy. The capacitor allows there to be multiple discharges becuase it stored enough energy to quickly saturate the coil during that VERY short amount of time. I DO agree that the coil itself may get hot enough to melt it though....

You are right about what the MSD 6A does Reaper, and MSD doesn't recommend upgrading the harness wires, or the connector itself, when installing their 6A CD unit.

On Edit: ( MSD does say you need a hotter coil with it though.)

Please, take a look at my last post, and tell me if you think my theory is right.

[lookin]

Quote:

Originally Posted by c2xejk With a conventional setup you would have 3 plug firings engine revolution. With the MSD it is fire some multiple of that. Thus there is no time for the wire to cool back down before the next firing.

That sounds very plausible.

[c2xejk]

When you make a grilled ham and cheese sandwich, the ham cheese and bread all melts at the same time, right?!

[kermit]

Well the the plug probably has the thinnest metal throughout the entire wiring system. If one spot is going to get hot because of too much current I would think that it would be there.

[lookin]

Quote:

Originally Posted by c2xejk When you make a grilled ham and cheese sandwich, the ham cheese and bread all melts at the same time, right?!

[lookin]

Kermit I guess so.

[c2xejk]

Quote:

Originally Posted by lookin

Not all materials melt at the same temperature... Additionally thermal conductivity can effect temperature. As well as airflow...

[roguetrip]

Do you see a carbon buildup paths from arcing? Usually the arcing (if bad enoug) can cause ozone which makes parts brittle with time, not so much to melt plastics. Since its not the wires, you could try to add some thin metal in the prongs to make a shim effect if you do see carbon arcing paths.

Another thing to try is to mount the coilpack somewhere away from the engine (firewall, pass side inner fender well), since it's mounted on the engine, once the engine has warmed could be just adding extra heat to a already hot coil.

[kermit]

Why is everyone trying to cover up the actual problem by trying to add more cooling?

EDIT: Is that the stock location of the coil??

[lookin]

Quote:

Originally Posted by c2xejk Not all materials melt at the same temperature... Additionally thermal conductivity can effect temperature. As well as airflow...

True. But ham doesn't melt anymore than bread does. Now cheese. That melts.

[kermit]

Quote:

Originally Posted by lookin True. But ham doesn't melt anymore than bread does. Now cheese. That melts.

Yeah, and you're not going to melt cheese on a icy hot pad either. The top of the engine isn't producing enough heat to melt the plastic. And if it was, cheese melts from the outside in, not the inside out.

...Unless you run wires through the cheese and run too much current through them. Check that first.

[lookin]

Quote:

Originally Posted by roguetrip Do you see a carbon buildup paths from arcing?

Yes I do, a little on the end of the connector, and don't forget that piece of the female connector pin that fell out of the harness plug. The arc between the connectors, melted through the metal connector sheathes, and that caused the low level thermal degradation of the plastic plug.

I think I know what caused the harness plug connectors to get sloppy. I always pull the coil plug after I do an oil change and refill with oil, to turn it over until I get oil pressure without starting the engine, and I see-sawed the plug back and forth to disconnect it last time, because it was a fresh tight one. Next time I will pull it straight out.