<VV> At Wit's End with HEI Ignition

Larry Forman larry at forman.net
Fri Mar 25 18:42:17 EST 2005


----- Original Message -----
From: "goofyroo at excite.com" <goofyroo at excite.com>
To: virtualvairs at corvair.org
Subject: <VV> At Wit's End with HEI Ignition
Date: Fri, 25 Mar 2005 17:10:43 -0500 (EST)

> 
> 
> Some of y'all have responded to my questions about the sudden HEI 
> ignition failure in my '63 convertible.  This is the Dale hybrid 
> system that's served me fine for six years.  (Dale hasn't answered 
> calls yesterday and today.)
> 
> I've tried replacing some parts and diagnosing others thusly, still no spark:
> 
> - New GM brain box
> - New Chrysler pick-up; wires are good
> - Tested a known good coil in place of 6-year-old Flamethrower
>    - Ohms check out OK
>    - Flamethrower produces a spark at the output when the - 
> terminal is grounded, then released
> - Rotor turns with engine
> - Engine ground is good
> - Ran 12V directly to + terminal of coil
> 
> None of this gets a spark out of the ignition wires, or even out of 
> the coil wire when it's held just a bit off the contact.
> 
> All that's left to replace are the brass-contact cap and rotor.  I 
> cleaned them up, and can't imagine how one could fail suddently.  I 
> even tested the rotor to ensure it is contacting the center post.
> 
> I'm at wit's end with this.  Anything I haven't checked?
> 
> Michael Smith

Michael,
Bob Helt is right as usual.  Some additional ideas:
1. You need to still ensure there is between about 9 and 12 volts on the POSITIVE lead of the ignition coil when you expect there to be ignition spark.
2. You need to ensure that the negative coil lead running to the distributor simulates shorting to ground and then releasing when you expect there to be ignition spark.  Measure at the coil negative lead and see if it is going the cycle from maybe around 12 volts to ground and then releasing.  And then you will have the spark at that release instant, just like you found when you used a short or screwdriver.
3. You can loosen the distributor and rotate it when making these measurements.  If you can rotate it about 60 degrees then you can be assured you will run a complete cycle for that particular cylinder.  You do not need to rotate the engine when doing this.
4. You can just place the high tension lead from the ignition coil about 1/4 inch from ground and check everything with the distributor cap and rotor off.   This is because at this point you just need the ignition system to activate and drive the ignition coil.
5. Check to see that the distributor gear pin is not sheared or that the brass drive gear is not trashed.  It is possible that for some reason the engine is not driving the distributor shaft.  Check that the rotor goes around with the distributor cap off and the rotor on so you can see it rotate when the engine is cranked.  At this point, it is hard to know precisely what you have verified, since we are not there looking with you.

Check these and let us know.  The good thing is that you are really getting close, you just don't know it yet!

-- Larry



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