The Stovebolt Site Forums The Parking Lot '60-'66 Trucks Ignition head scratcher...

Greetings all,
I guess I'm the new kid in town (here).
I just swapped out my 54 yr old 292 for a 70 something Mexican version in my 64 C20. I got the motor from
my younger brother, cause it came in the 66 he got, and he wanted to put a V8 in it. This swap allowed me
to continue using the rig as my daily driver, while wrenching on the original, and bringing her up to what I
know she's capable of. Enough with the prelude.
So. While my brother was running it in his rig, he put an HEI in it. It always ran "ratty". So after messing with
it after we put the engine in my rig. I said screw it. It sounds like the coil has a short in it. So put the points
dist from my motor in it, and that was that. Except, it never ran as smooth as my original motor did. I worked
through the whole thing checking for anything amiss. It acts 100% like electrical. But I rebuilt the carb, and
checked for any vacum leaks. But she still "crackles". Consistently at just above 2000, and periodically when
stuffing my foot in 'er when starting out from a slow speed.
A couple things. I know mine came with nichrome wire from the solenoid to the bat on the coil. But the previous
owner(s) fancied themselves as electricians, and eliminated it. I found this out the hard way. As after I bought it,
and started driving it around, it started eating condensers like candy. I knew what to do immediately. But not
being able to find the wire. I had to settle for a ballast resistor. I never actually checked the ohms on it. But
figured it should reduce it to 6 some volts. I guess I should *actually* check. :rolleyes:
Anyway. Unless I replace the coil in the HEI, and go with that. What I'd really like to do, is make it run correctly
*before* I start changing things. Cause that just adds additional variables into the mix, and will only add insult
to injury, if things act at all strange after changing out the points for the HEI. I guess, since I'm inclined to think
voltage might still be a problem; does anyone have any good sources for the original resistor wire? Sure. I could
simply run another ballast in series and surely get the voltage in range. But why not do it right the first,... err second
time.

Thanks for anything anyone feels they'd like to offer.

--Chris

A ballast resistor actually reduces the voltage to somewhere between 7 and 9 volts which should be adequate for your application. Source one from a late 50's GM product. Don't add another one. The spark plugs could be different for for a point vs HEI application. The gap most certainly is. Also, do a compression check. All troubleshooting starts from there.
Fred

Sun Electric Company said it best- - - - - -"We Test, Not Guess!" That slogan was on every piece of test equipment they sold back in the 1950's. Over-voltage in the primary system burns points- - - -I've never seen it damage a condenser in the past 50-something years.
Jerry

Thanks for your reply, rfs56trk!
Right you are. So I got off my DA, and actually put my voltmeter to it, and discovered there was
3.5-9 volts when also attached to the coil.
Hmm, a closer look, revealed that in one of my earlier forays (dealing with the dying condensers
I mentioned earlier). That I had found, and run the Resistor wire from the solenoid to the "fake"
ignition switch. With the intention to rewire the entire mess when I got an actual Delco-Remy
switch for my year (new). So The voltage is still a bit of a head scratcher. I've got the new key,
and switch on its way. So I think I'll simply wait till it gets here. Rewire that section of the harness
in its entirety, and check the results. I'd attempt to salvage the harness. But it's been butchered
so badly. It would make more a mess, than help. :rolleyes:

Thanks again for the reply, rfs56trk

--Chris

Heh. Surprised I wasn't called out on that earlier.
Well, as you'll note in my reply to rfs56trk. I actually got off my DA, and *did* check it.
As always. Thanks for keeping me honest, Jerry.

--Chris

With a Delco "12 volt" coil and a ceramic resistor for GM vehicles from the mid-1950's to the early 70's, you should see about 9 volts at the coil + terminal with the ignition on, points closed, and engine stopped. Since charging system voltage against a fully charged battery should be 14-something, voltage at the coil will be slightly higher, maybe 10.5 or so while running. Either way, the resistor should drop about 1/4 of the applied voltage. It sounds like you've been running too much primary resistance, resulting in low firing voltage to the plugs on acceleration. Be sure you have some type of resistor bypass system in place to supply full battery voltage to the coil during starting.
Jerry

Right on the money, Jerry.
When I bought it, it had one (non-resistence) wire from the solenoid to the bat on the coil.
I only discovered this, as the truck would continually start stuttering, and eventually die.
Then unable to start. I initially suspected points, or coil. So bought both -- I know, doesn't
help final diagnosis. But I wanted to start fresh, and see where it went. Anyway, some
30 - 50 miles later. Same problem. So I grabbed a couple condensers. Replaced it. Off
she went. OK. Now's the time to discover *why*. I started through the ignition circuit,
and low-and-behold, I discover the unresisted wire. So I locate the resistor wire, which
still existed (yellow fabric insulation), and cobble it into the circuit. I also cobble the putple
wire from the other terminal on the solenoid for the "start" circuit. I don't like the new
arrangement, and intend to rewire the whole harness. But it came with a s#!tty cheap
switch, and I've got other things on that circuit I still need to fix. So, I go with this for
now. With the intention of ripping the whole mess out, and start anew.
I'm now at that point. I've got an OE switch on it's way via FEDEX, and a new HEI
already in hand, and all the other stuff on the harness has been sorted. Given that I've
*mistakenly* overlooked the fact that I *did* have resistance on the bat side of the
coil. I'll simply remove the unnecessary ballast resister I added, which *should*
return some 6.5 - 9 vdc. But that's where I was *before* I started, and it "crackles",
or "stutters" stabbing the throttle while at 5-10mph, or just above 2 grand. But then
smooths out around 26 hundred, and remains smooth past 3 grand. It only stutters
at low speed for a bit, then smooths out. Feels electrical. Kind of like a loose wire might.
But nothing loose, and while I have considered the plug on the firewall. Given it happens
so consistently, same places, same times. I've pretty much ruled that out. I'm now
beginning to wonder it that Olds "single" wire 80 amp alternator I replaced the old one
with might be leaking AC? Bad diode in the bridge. I dunno. It's pouring rain today.
So I'm not inclined to deal with it right now. I've got to get my '86 735i out of the garage.
So I can start using the garage again. The rainy season seems to have started.

Thanks!

--Chris

When doesn't it rain in Washington? Down here in Tennessee people go out in the sun and they get a suntan. In Washington state they go out in the rain and rust!
LOL!
Jerry

You'd think!
While I was born in Oregon. We moved up to Washington when I was just 2, and as long
as I can remember. We didn't tan, we *rusted*.
But here in the last 5 yrs, or so. I can count the times it rains from May through October
on one hand! It's great for working outside. But it *ain't* Washington weather.
That sun you talk about down in Tennessee sounds nice. But it's pretty dang hot. Isn't it?
Great whiskey tho.

--Chris

Great for motorcycle riding, too! I rode my Harley to my 55-year high school class reunion a couple of weeks ago. I live 30 miles from Lynchburg- - - -home of Jack Daniel's!
Jerry