#6 cylinder not firing

[FastWoman]

Green tape?! Are you serious?! Hmmm.... Yeah, that's where I'd look.

[BadDog]

I took a quick look at the magnet ring before I left for work this morning. It looks like the tape has lifted a little and folded over in at least one spot. That may be the issue, or it may have happened when I tried to see how much play there was in rotating the rotor counter-clockwise and back, and the maybe rotor damaged the tape. I'll have to take a closer look at it tonight.

I'll probably swap the old points back in tonight if I can find the old the ballast resistor. If points work OK, it's a Pertronix/magnet issue and I'll look into a replacement.

I'll probably also go ahead and order a remanufactured dizzy, seeing as mine's probably pretty worn, and a new one will probably last close to another 38 years (and they seem to be in short supply!)

[FastWoman]

FAIW, Autozone sells a remanufactured dizzy for around $100 with a lifetime warranty. These things don't actually last anywhere near 38 years, due to a bad breaker plate design. It doesn't take long before the breaker plate freezes up and the vacuum advance sticks. The reman parts often aren't very good, but I figure if the R&R is an easy one, why not do it? So far my reman AZ dizzy is doing great. My original reman AZ alternator did start putting out slightly too high a voltage at one point, and AZ was very good about replacing it.

[ezzzzzzz]

The magnet simply triggers the sensor which fires the coil. If it's working on 5 cylinders then the sensor is fine. Some folks remove the tape and epoxy the magnets into place. I just installed a Petronix in my 71 and it is working fine (although I burned out the new coil by removing the ballast as directed in the instructions). I will probably pull the rotor assembly and glue those magnets into place before I make the 12 hour drive to Savannah for ZCON2011.

[Zforce]

Definitely get rid of the green tape with epoxy.

[FastWoman]

Ezzzzzzz, I don't know the specifics of the Pertronix rig, so I'm just making an educated guess:

I would presume different magnetic lobes correspond to different cylinders. If there's anything marginal about the operation of the system (e.g. distance of sensor from lobes being incorrect or marginal sensitivity), and if there's any difference at all in the strength of the trigger for each cylinder (e.g. magnetic field strength generated by each magnetic lobe), then at least one cylinder will be prone to fail while the others are still (barely) operational.

[Zforce]

Pretty sure Pertronix is a hall effect trigger.

[ezzzzzzz]

For the L6, the Petronix unit is fixed at 28 degrees dwell. There are two mounting screws with no adjustment possible as delivered. It is a simple hall's effect sensor. There is a possibility of some failure due to a magnet strength but these things are so simple it's hard to be sure. Hopefully, he didn't follow the instructions. For what it is worth, the black lead from the distributor goes to the (-) of the coil. The red lead goes to the 12V side of the ballast resistor not the (+) of the coil as directed. The ballast should be used unless you are CERTAIN that the coil will operate on 12V. I burned up my 3 ohm coil following Petronix instructions of removing the ballast resistor. Swapping in points and resetting timing will point to the problem quickly.

[BadDog]

3 words:

Stupid

Green

Tape

Yes, one of the magnets came out. The tape wasn't unwound or anything, the magnet just pulled itself through the tape! Superglued it back in place and drove 80 miles with no issues at all.

Fastwoman - reman'd dizzies are functionally NLA from AutoZone, Parts America, and NAPA. All 3 said none available. Orderd mine from AZ before I even saw your post :-)

ezzzzzzzzzzzzzzzzzzzzzzzzz - I've been running my Flamethrower coil (3 ohm) without the ballast resistor now for 4 years, no issues there. Plus, MSD says to remove it.

I'm still going to put in my new dizzy when it comes. There's a little play in the shaft, the gears may be a little worn.

Thanks to you all!

Edited May 19, 2011 by BadDog

[FastWoman]

Yikes, they're now NLA? That makes me wonder how they're going to honor the lifetime warranty. I'm sure more will become available, but I suppose the supply will be trickling away. I guess I got in towards the tail end of a good thing.

Anyway, glad you found your problem!

[BadDog]

Yep, rock auto and NAPA both offer a rebuild service, but have no stock. NAPA said that rebuilds are only 80% successful. No guarantee the rebuild will be OK if you give your old one to them and wait 10 days