'64 GTO dies after starting???

[ALLKAR]

My buddies '64 GTO will not stay running after it turns over. The car was running fine before this. Turn the key to start and it will run, but dies as soon as the key is released. It's like no power to the coil.

Any ideas???

Thanks

[dhutton]

There is a length of resistance wire in series with the coil that is the coil current passes through when the car is running but not while it is cranking. Same thing as the ballast resistor in a Mopar. It is probably open.

[ALLKAR]

What needs to be replaced?

[dhutton]

What needs to be replaced?

Probably that length of resistance wire. You're going to need an ohmmeter to troubleshoot this. If you don't have one or know how to use one it's time to find someone who does.

[ALLKAR]

Got ya :twothumbs

Thanks for the help.

[dhutton]

I found a wiring diagram for my 64 GTO on the net. Here is one:

http://home.mchsi.com/~magicv8/indexpics/wiring64pglide.jpg

Don

[ALLKAR]

That helps a lot. The one I found did not show the resistor wire.

[Footjoy]

ALLKAR
That is a nice Nova. Do you still own it?

[ALLKAR]

Thanks, yeah. Cleanest car I've ever owned. Zero rust!

[Footjoy]

I have a 70 that I am trying to finish so I can get a first gen Nova. Its that car I never owned.

[wmhjr]

That same ballast/connection links IGN1 and IGN2 on the ignition switch. I missed it on the wiring diagrams - not noticing that it essentially bridges the two circuits. As a result, when wiring up my MSD 6AL2 I had the same general problem. Either the ignition fired when the starter was engaged and died when in the "run" position, or it would not fire when starter was engaged but WAS energized when the key was in the run position.

Does anybody know why GM even did this? It makes no sense to me. I ended up just bridging the two circuits so the ignition is hot either in start or run.

[John Wright]

That same ballast/connection links IGN1 and IGN2 on the ignition switch. I missed it on the wiring diagrams - not noticing that it essentially bridges the two circuits. As a result, when wiring up my MSD 6AL2 I had the same general problem. Either the ignition fired when the starter was engaged and died when in the "run" position, or it would not fire when starter was engaged but WAS energized when the key was in the run position.

Does anybody know why GM even did this? It makes no sense to me. I ended up just bridging the two circuits so the ignition is hot either in start or run.
.....maybe so it wouldn't burn up the points?(if they happen to be closed or just barely open when the power was supplied)

[wmhjr]

.....maybe so it wouldn't burn up the points?(if they happen to be closed or just barely open when the power was supplied)

I guess I'm still not understanding it. Call me dumb - I know.

If the ignition swith IGN1 and IGN2 circuits are completely separate, and the coil power wire passes through the ballast resistor to bridge these circuits. The coil has to be hot in both circumstances (IGN1 and IGN2). So how is the design preventing damage to the points? Serious question.

Second question - as I'm running a Pro Billet dist and a 6AL2, is there any problem with me simply bridging those two circuits?

Thanks!

[dhutton]

I guess I'm still not understanding it. Call me dumb - I know.

If the ignition swith IGN1 and IGN2 circuits are completely separate, and the coil power wire passes through the ballast resistor to bridge these circuits. The coil has to be hot in both circumstances (IGN1 and IGN2). So how is the design preventing damage to the points? Serious question.

Second question - as I'm running a Pro Billet dist and a 6AL2, is there any problem with me simply bridging those two circuits?

Thanks!

The idea is to reduce the current through the points once the car is running. If you convert to electronic ignition you have to bypass/remove/replace that resistance wire to keep correct voltage applied to your electronic ignition.

[John Wright]

I think the resistor wire was to cut voltage so that it didn't cook the points....

ie.
if you left that wire in place and ran a HEI there wouldn't be enough voltage for the HEI to function very well.(found out the hard way after hours of trying to figure out why the ignition was busting up when I rev'd it under load)



EDIT: Whoops....faster typer^^^^^^what he said

[wmhjr]

OK, so in a standard points ignition, you need the full voltage during crank to start the motor (IGN2), but voltage is reduced by the ballast/resistance wire in "Run" (IGN1). In a HEI or newer MSD type electronic ignition, you need full voltage in both modes so simply wiring the two circuits together is correct. Right?

Thanks for the lesson, guys!

[John Wright]

yeah...I think you got it.

[wmhjr]

Thanks, John. It's clicking now.

[MonzaRacer]

OK on old vehicles with points system they use a resistor wire to cut the voltage down the the points carry. Now on older GM cars they had an issue with hard starting and it was rectified with a relay wire also tied in to the ign coil wire from the R terminal on the starter. This fed full 12 v to coild for cold starting.
Now lets get to ignition one and ignition two. Now lets say you want to separate items powered on in either the run or accessory position.
So like some cars the radio, wipers, alternator and certain other things are tied to say ign one and its hot in run only. And ign two is only hot in run and acc.
Now if you tie both together then you will power up you ignition or fuel pump or what ever you have hooked to keyed power.
A proper inspection with a test light is in order. Now if you have aftermarket or HEI ignition pull the engine harness from firewall (one bolt in center and both engine and headlight wiring will come loose and then you can separate the two.
Now the fun part, get some carb cleaner, a small pocket screwdriver and maybe brake clean, which ever works best and follow the woven white cloth covered wire from the distributor + terminal back to the firewall connector.
Now if you may reuse the points later on, ie unmodify the car, simply fold that wire and the wire leading down to starter R terminal back into the harness and tape up. If your never going to unmodify it snip it about 1/2" from black connector if you dont have any new factory terminals and solder a new 12 gauge wire and run to the new ignition. Now if you have extra wiring, the terminals have what is called a strain relief, it crimps over the insulated part of wires, you can open that and lay the new wire inside that, fold them over to hold it then solder it, and then reinstall it.
Its very easy and if you do it fast you dont even really have to remove it from the black plastic terminal block. To make it look stock you can push the tar like stuff back around the wire , me I use small piece of shrink tubing to insulate.
I would not tie both ignitions together as they are separate for a reason.

[wmhjr]

Lee,

Thanks, but in my case there is nothing whatsoever remaining in the car that is "OEM" except maybe the core of the perimeter boxed frame (which has been reinforced), the remains of a '70 400 block (which has been magnafluxed, sonic tested, bored, honed and zero decked) and some sheet metal and trim. There ain't goin back to stock. Every single wire is new and is not stock. Every circuit was planned and put in by hand, and routed WAY differently than stock. So in my case, the question about why it was done that way at the factory was just to satisfy curiosity. I know exactly where every ciruit is run, how it's run, what wire it uses, how it's fused and how it is energized in the car. Bottom line is that the reason it was done by GM should have been apparent to me (just a "Doh" moment for me). But it no longer applies in any way. Going back to stock would require completely rebuilding the car from scratch and would require removing the body again, ripping out the firewall, etc. Just ain't never gonna happen. Thanks, though.