<VV> New Voltage Problem

[goofyroo at excite.com]

It sounds as if we are working on similar problems.  Although, I do not have the high voltage at the coil.  Just diminishing voltage at the fuse box as RPM rises -- but only when outside temps are above 85F or so.  Eventually the engine quits for lack of spark.  It will restart after a few minutes' cooling.

I've been corresponding here and off-list with Dave, Matt, and Bob (Helt), who've helped me narrow it down to the ignition, probably the wire between the ignition switch and the coil.  (I have no resistance wire; just 12V direct to the Dale HEI system.)

I hope the info below helps in your diagnosis, too.

Hi guys:

I thought I'd reply to you all with one message since I tried everything you've suggested tonight and had success with one of the ideas.

I jumped from the alternator + output post all the way to the battery in the trunk, going around the existing + cable. [EDIT: also jumped the engine ground strap directly to the batt - post.] I was quite a sight rolling around the neighborhood with jumper cables running down the body! But no improvement in readings.

Then I switched the jumper to the alt FIELD spade terminal, wiring it directly to the battery instead of the alt + output post. No change. (Good try, Matt.)

Finally I just ran a direct wire from the alt + output post to the + terminal of the ignition coil. Success! Voltage stabilized at 13.5 (even with AC running) and now voltage rises with RPM. The relationship between voltage and RPM used to be inverse once the heat set in.

I have the Dale HEI ignition wired directly at 12v, so there is no resistance wire.

So now I wonder how to fix it? Suppose my ignition switch or wires up in the dash need cleaning?

Y'all have been terrific to help with this. Thank you.

Michael

> Joel wrote -
> A buddy's 64 'brier runs like poo the higher the rpm rises. It's a LM 110 
> with a high output internally regulated alternator. I measured the voltage 
> at the coil tonight, and it's showing 16volts consistently throughout the 
> rev range. (Positive lead to the Positive terminal on the coil and Negative 
> lead to a good ground, correct?) He's running a Pertronix I and a Pertronix 
> Coil.

P.S. Has he checked the timing?  Is it advancing with RPM?

Michael

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