[Ram Air IV Jack]

Originally Posted by unruhjonny

at the risk of making someone here re-read my experience with electronic ignitions on a points car;
I was introduced to the bad side of electronic ignitions when the most reliable one out there (a GM HEI, with no foreign parts) died on me;
the culprit was the magnetic pickup.

I learned right there that electronics WILL let you down;
I also learned that a mechanical issue is easier to diagnose than an electronic one.

When these points conversions first came out, I thought they were cool;
I’m now fully on board with old fashioned “never going to leave you stranded” points.

Years back my 77 Olds Cutlass stopped in city traffic and a friendly neighbor helped me to a local service station. It was repaired and I was told the stock GM HEI failure is common because of the constant motion of the vacuum advance in the unit. The wires to the pickup flex with the vacuum advance and will eventually break and then no spark. Happened to another 77 GM car I had too but that occurred during body repair, so I wasn't stranded. I'm keeping my stock points distributor on my 69 GTO.

[Schurkey]

Originally Posted by Formulas

on cars that originally had points they also had a wire providing full batt voltage from starter solenoid during cranking, that's what did my unilite in during a compression test...
...it would be easy for me to claim mallory unilite is junk, my installation was junk

Yeah, GM kept that a complete secret. Who would have ever guessed that there was a resistor bypass wire? Certainly not an outside company designing products to be used on GM products. (Moreover, with the starter engaged, battery voltage should be reduced due to the heavy current/amperage demand of the starter motor.)

No wonder Mallory didn't protect their module from battery voltage. They didn't know that battery voltage would ever, ever, ever be applied to the power input of the module. And besides, then they can advertise and profit from a separate "protection" module to be used with their ignition module.

OTOH, the 4-pin HEI module is protected to 17+ volts, (at least for short-term use) 'cause that's what a GM alternator can produce when full-fielded. Kinda like GM was thinking ahead, had proper engineers, and cared about reliability.

[lust4speed]

Originally Posted by grivera

Are Mallory Unilte dizzys as unreliable as Petronix or user error supplying a full 12 volts?

I heard nasty things about those Mallory modules after I purchased mine and live in fear that it will fail. 1985 is a very long time to live in fear .

At least the Pertronix modules get to the end very quickly and don't leave you hanging.

[Sun Tuned]

Clearly some of the aftermarket choices are rather glass jawed at times. Some just plain aren’t worth a hoot to start with.

After messing with this stuff some 30 years or so, I’ve developed a couple observations that might help.

First, no one gives it a second thought, but never do ANY welding on the vehicle without first disconnecting the battery. I know this will NEVER happen at a muffler shop. At least I’ve never seen it done. Unless your gas welding the pipes/mufflers. Been one really damn long time since I’ve seen that done.

The electronics in these “kits” and even in the HEI modules do not lend themselves well to welding practices.yet many people never think about exhaust work and battery connections and electronics. Especially the diode rack in the alternator.

Don’t forget engine to frame and body grounds and nice tight clean connections. You’d be surprised over the years how things manage to become “lost” or have simply disappeared or got loose.

It also wouldn’t hurt to check voltage output when running on these cars. Voltage regulators CAN and Do get out of spec. Have seen several cars just in the last 6 weeks that were over 15.7+ volts.

The HEI pickup coils really weren’t that problematic on breaking the white/green wires. At least until the heat baked them. Which will happen if aged enough. If you look at one upside down there is a white plastic connector where the wires go into the frame of the coil. The wire insulation will crack right just under that plastic and you may not see it from the top, , but when turned upside down it’s right there. The easy solution here is to take the coil and place a little RTV at that junction before the wires insulation cracks and especially when new. This acts as a real nice strain relief for this location. This is a much better solution and heads off a potential age/heat related problem before it starts.