Bluestripe67

The facts: distributor has a Mallory Unilite, ignition is controlled by a Jacobs MileMaster CDI. Plugs and wires are 2 yrs old. Up until 2 months ago everything on my '67 was purring along. Then on a sunny day while in the middle of a 200 mi. cruise the car shut down for a nano second. It was a physical jolt. It restarted it's self and I kept going, then it did the exact same thing again. My buddy and I look at each other and wonder, WTH! About 2-3 miles later, it shut down again, but did not restart, I kept on rolling, but restarted with the key. Later in the day it did it again. It's interesting what the contrast is from a nice growl too dead silence. I made it home, rested and looked things over the next day, and found nothing obvious. In the last two week I have taken the car out on two or three very local drives doing errands etc. All short distance and duration, nothing happened. Thank God, my wife was with me on one drive. Last night I went to a cruise in 20 minutes away, no problem. Later I took a 10-15 mile drive (45 min- 1 hour engine operating time) and it did the nano second shut down thing 3-5 times. A couple of those times I had to restart it with the key. Got it home and now I want the thoughts of the CF before I get into it.
Here are two, thoughts I have gleaned from the CF.
1. I will check the bulkhead connections and look for corrosion.
2. How suspect could the coil be? It's 2 yrs old at the most. It's a Flame Thrower 1.5 ohm.
3. Is heat, built up over a long periods of time, the enemy of the coil. Dennis

Frankie the Fink

There is a VERY interesting article in this months NCRS Restorer magazine about a C2 owner chasing a similar problem for weeks and it turned out to be his distributor hold down clamp not.providing a good enough ground for his ignition system. His symptoms were very similar.

mrg

Sounds like an imminent coil failure waiting in the wings. The symptoms you mentioned describe very close the experience I had on a road trip last summer.

What turned out to be a hard start condition on every restart after a gas stop or some such eventually turned into nano second misses, then short pauses, then longer pauses until the engine finally quit for good.

No question now the problem was in the ignition, not in fuel delivery as originally thought.
A spare coil carried along on the trip saved the day.
The coil that failed was an Accel brand that saw about 8K of use before it gave up the ghost. If you've got a spare coil I'd give that a go.
John

Bluestripe67

I'm into it! Checked all the ignition connections at the coil and others in line of the CDI system. Checked the distributor clamp. Cleaned it, tightened it. Separated the bulkhead connector very carefully. Some corrosion, but not bad. One interesting thing, the main 10ga red wire does not disconnect as the others. It just slides through the female holder. Is this right? I expected it too disconnect with the others.
I have another coil that should be good since it was in the ignition system prior to the current one. How do you test a coil? Thanks for the tips so far. Dennis

vettepoor

Dennis - I would suspect your coil. I had a Flamethrower that lasted less than a year before it puked. Same symptoms as you describe.
Years ago, my 65 would run fine and just quit totally until it sat for a few minutes, then would start and run fine. Turned out to be a bad ballast resistor. Good luck.

John

Nowhere Man

Dennis I believe what you describe for the red wire is how GM told the service workers at dealer ships how to fix a issue that red wire causes. This may sound funny but smell the coil. If it has a burnt electrical smell that could give you a clue if it's going bad. That's how I diagnosed a bad coil in one of dads car

Bluestripe67

Guys, the more I dwell on this "electrical ghost" issue, the more I'm thinking it's the coil. Correct me if I'm wrong, but an oil filled coil absorbs heat, right? These events always happen after I have been out driving for at least an hour, allowing the heat buildup. I changed the coil last night. Today I'll do some road time.
Keith, The way the red wire is connected still intrigues me. What if I needed too disconnect it? I guess you have too pull the interior fuse side of the panel! I hope the coil IS the problem, that way I won't need too dig deeper. Thanks for the replies! Dennis

Frankie the Fink

Flamethrower coils are crap.
One failed in my '63 - will never have another....too many other quality options...

capevettes

While it could be the coil, don't rule out the control module with the Mallory Unilite. I have had more than one go South on me. They would work intermittently as they begin to fail.

Bluestripe67

I have just finished testing the coil and module per the Mallory test procedure on YouTube. Coil reads 12.1v, but the module appears too be stuck on 12.1v. This indicates the module is damaged/bad as stated in the video. I installed this module in 1990. I guess I'll get a new one this week. Dennis

capevettes

That sounds like it Dennis. They are prone to failure, especially when you use a battery tender because of the electrical spikes they cause. Since I stopped using the battery tenders I haven't blown out another one. You did well getting 25 years out of it. I hope that's the fix

Frankie the Fink

You really need the accessory surge protector for that Unilite if you don't already have one. They are real prone to voltage spikes.

Bluestripe67

Frankie, I assume this surge protector is a Mallory or Accel part. Dennis

20round

10-4 frankie !!!! i just read it myself !!! very good one!!!

Frankie the Fink

Yes - here it is mounted on my 67 Chevelle (see red arrow).

Mallory calls it an "Active Power Filter". I wouldn't run a Unilite without one personally.

Bluestripe67

The ghosts will go away. Ordered the new module and power filter from Summit. Thanks for the tip Frankie. Dennis

Bluestripe67

Maybe the ghost didn't go away. Installed the new module and the inline power filter. Checked every connection again and then some. Turned the key and, ZERO! No sound/start dead silence. Turned on headlights all lighting is normal. This tells me the battery is good.
Now I'm back looking at the bulkhead connector. If you recall on post #4 & #7 I asked about the red wire not having a pin connector. It just goes all the way through to the back of the interior connector. I have separated the bulkhead connector. At this point it looks like an old (car in original owner's hands) solder connection not wrapped in tape. I understand some guys will bypass all this and run a new #10 wire to the horn relay. I just looked at the fusable link at the starter. It looks fine, no indication of melting. What are your thoughts? Calling Dan Aykroyd. Dennis

Milliamp

I had the same thing happen to me with the same type of ignition, if I can remember Mallory systems use an infrared LED and a shutter wheel to pick up pulses. When mine got hot the car would die and would not start until I let it sit for several minutes, I found the plate that held the shutter wheel was epoxied to the base and when it got hot it shifted and the shutter wheel could not receive its signals from the LED. With this type of system timing accuracy goes down the tube as you approach 6000 RPM also check for dirt and moisture and wipe the LED lens with a soft cloth. Hope that helps. Tom

Frankie the Fink

The starter motor should turn the engine even if the Unilite were malfunctioning....

65GGvert

Troubleshooting that new fangled electronic stuff can be problematic, eh?