Re: flacky pertronics?

[Eric Hegstrom <ehegstrom@domain.elided>]

Well I've already undertaken all the steps you suggest except one ( and
I have been wondering about that one all along). That is powering the
pertronics off full 12v instead of after the resistor.

Hmm. Are you saying the stock coil didn't have a ballast resistor. My
setup appears to be stock with one. When I had them look up the coil I
needed they gave me the borg-warner one I mentioned earlier and it had a
big sticker on it that said you must use with a ballast resistor. I even
measured the wire feeding the + side of the coil to make sure it was
appreciably under 12v (and I yes jiggled the balkhead connectors to
confirm they weren't acting as a resistor :) .  I also picked up what
was claimed to be the stock ballast resistor ( only $4 ) so I could make
a hot-wire jumper so I could hook the coil directly up to the battery to
confirm I wasn't getting some sort of intermittent short or open.

So in your recommendation #1 are you suggesting that I remove the
ballast from my current coil? I am guessing that his depends on the
internal coil resistance. What is considered low resistance and what is
considered high resistance. I will get the trusty multimeter out and
check it.

I will try step your recommendation #2 if I can ever get away for lunch.

I am tempted to rip the pertronics out. Build a little test bed and hook
it up to the $20K digital scope sitting next to me at work and get the
heat gun and big-ass lab power suppplies out and do some real testing.
Seems kind of excessive though I'm sure my co-workers and boss would get
a kick out of it.

Peace,
Eric

"John A. Landry" wrote:
> 
> The aliens commander decided Tom Mandera <tsm1@domain.elided> would make a
> perfect specimen for dissection, and he yelled...
> 
> >If you left the resistor in place, you should've been fine...
> 
> Wait a minute!  This depends.
> 
> Eric... The bottom line is this...
> 
> The Pertronix cannot handle "switching" full or nearly a full 12 volts
> coming through the coil.  That much voltage will cause the Pertronix to
> overheat and fail at some point, just like breaker-points will arc, burn
> and fail in time if fed too much voltage.
> 
> So just like breaker-points, the Pertronix needs to be protected from
> excessive voltage by the higher resistance of a stock type coil *or* by the
> resistance of an external ballast resistor / resistance wire in the
> ignition circuit.  The Pertronix does not need both.  Using a higher
> resistance stock type coil *and* an external resistor could mean inadequate
> secondary spark being developed in the coil... which means a you could get
> a weak spark at the spark plug tip.
> 
> If you're sure that coil is a stock version (verify by checking the
> resistance across the small primary terminals on the coil per the Pertronix
> instructions), then do *not* use a ballast resistor also!  If the coil has
> low resistance (as is typical with aftermarket high-performance coils such
> as the MSD Blaster, etc.), then you must use a ballast resistor to increase
> the resistance and protect the Pertronix.
> 
> Before you yank the Pertronix assuming it's the culprit, check some basics.
> 
> 1. Verify the coil is actually a stock type and if so, disconnect the
> ballast resistor.  However, I'd recommend you physically leave the ballast
> resistor in place in case you do need to drop the points back in someday.
> 
> 2. For best results, make sure the red power supply wire from the Pertronix
> is connected to an ignition switched *full* 12 volt power source... not a
> lower voltage source after the ballast resistor.
> 
> 3. Verify the air gap is correct between the magnet wheel and the Pertronix
> module.
> 
> 4. Make sure the magnet wheel is not loose and free to move around under
> the rotor.
> 
> 5. Check all of your, and the old previous wire connections in the ignition
> system are clean and solid.
> 
> There's always the possibility the Pertronix module is having problems, but
> this is extremely rare, so I'd really check things out carefully first
> before focusing on it.  You'd be terribly aggravated if you had it replaced
> by Pertronix only to find the problem still there.
> 
> Good luck,
> 
> John L.
> --------------------------------------------------------------------------
> jlandry AT halcyon DOT com      |
> Conservative Libertarian        |  "The road to  tyranny, we must never
> Life Member of the NRA          |   forget, begins with the destruction
> WA Arms Collectors              |   of the truth."
> Commercial Helicopter - Inst.   |                     William J. Clinton
> http://www.halcyon.com/jlandry/ |    10-15-95, speech at the Univ. of CT

-- 
Eric Hegstrom                          .~.
Senior Software Engineer               /V\  
Sonoran Scanners, Inc.                // \\          L I N U X
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