I have installed a Pertronix Ignitor and coil in my '68 Olds 350. Car ran great and I put 100 miles on it to and from a car show. Drove it into the garage and now the car won't run. It fires, put will not continue to run. I replaced the fuel pump and I replaced the Q-jet with an Edelbrock - no help. It has new wires and plugs. Someone told me temperature fluctuations could loosen the screws holding down the electromagnetic ring and cause excessive air gap. I've been running this same ignition in my truck for several years without incident. Anyone have any experience with the Pertonix Ignitor or coil that you may have experienced these symptoms? Or other ideas? Thanks.

 

I don't have any bright ideas other than the obvious recommendations, like verify that you're getting spark like you're supposed to. If not, then check voltages on the ignition system and disassemble the distributor and check to assure that the gap is still what it's supposed to be.

If your car is firing, but not continuing to run, that makes me wonder whether you've got good wiring and voltage in the crank circuit, but not in the run circuit. I'm not familiar with the voltage differential on the primary side of the ignition system for a 1968, but I know that for my 1962 it gets about 12V during cranking and 6V during running.

There are FAQ entries at pertronix that relate to problems like yours. Most often, they're due to low voltage problems. Check your running voltage at the primary side of the coil under both start and run conditions, post it here, and read those FAQs. If I had to guess I'd say that you've got drooping voltages because of a bad connection or to much resistance in the ignition circuit. Bear in mind that the ignition module and the ballast resistor (or ballast wire) form a voltage divider that defines the voltage across your ignition coil primary. If you find low voltages are a problem than re-scaling your voltage divider might be the answer.

 

How about reinstalling the points to see if that cures the problem?

 

I just had a similar issue with my 1181 LS (non magnetic ring version) Check your grounds. My ground strap from the firewall to the block was loosened up somehow. Tightened it up and it solved my problem. Noticed you said you just put it in recently; You are running your power from "pink" ignition one right? Not from the original resistance wire.

 

Please explain exactly what you mean by this.

As Bob noted, it sounds (depending on what you mean, exactly) as though you may not be getting power through the main wire for the Ign circuit.

Welcome to ClassicOlds.

- Eric

 

Was it running fine when you parked it then shut it off? A jumped timing chain will prevent a car from starting but it will sound like it wants to start. Though check all the simple things first but, if it has high millage, is on the original timing set and you still can't solve the problem look at a possible jumped chain.

 

As Eric asked, please clarify, is it firing with the key turned to engage the starter, but shuts off when you release the key? That would indicate the wiring in the run circuit is the culprit. Have you checked that the wiring to the coil is connected and tight? I had an ignition switch go bad once, and it lost a good contact in the run position and it wouldn't run.

 

I have always found it interesting that over the years, one never sees posts of, "Hey, I installed a YOUNAMEBRAND electroinic ignition and my car runs fantastic. Of equal interest is the fact that most folks who do install 'em make sure to carry a spare distributor/points at all times.

Just sayin'?

 

I agree -- some clarification is needed. If you could address the following points that might help:

- When you say "It fires, but will not continue to run," do you mean that the engine starts when you turn the ignition switch to crank position, and dies when you release the ignition switch to the run position?

- Have you checked for spark when in the run condition?

- Have you isolated the problem to fuel delivery or spark?

- Did you check the screws for gap changes? If the screws haven't moved, then there should not be a problem with play causing gap to increase. This is an olds application, and Olds don't have the problem of gap increasing under load.

- You never mentioned whether you have the Pertronix I, II or III system. You also never mentioned what type of coil you have. It's absolutely critical that you've matched the right ignition module with the right ignition coil. Please list what you have.

- How did you wire the Pertronix module into your car?. Did you use a ballast resistor or a ballast wire or neither, what was the impedance of the car's resistance element and of the ignition coil? Did you tap into the car's ignition switch wiring or add new wires? It would really help if you could draw a schematic that accurately represents your installation.

If I were in your shoes the first thing that I would do would be to measure voltages at the distributor coil primary under crank and run conditions.

 

Hey, I installed a Pertronix electroinic ignition and my car runs fantastic. I DO NOT carry any points in my car.

 

There's always ONE wiseguy...



By the way, nice post, Bob P.

- Eric

 

Maybe a little bit of a wiseguy but it is 100% the truth. Okay, a good bit wiseguy.

 

The engine I'm using now actually came with a Crane electronic pickup, and I switched it back to points because I didn't like the way that it made the tach read funny when I was tuning it up - I didn't want to take any chances.

I also carry an extra set of points and a condenser with me, as well as the Crane unit.

Some of us have less faith than others.

- Eric

 

Wiseguy?!? I'm also not worried about carrying spare ignition parts -- In the era of electronic ignitions I think the only guys that need to worry about carrying a backup set of points and a condenser are the guys who are running points and a condenser... <ducks for cover>

My thinking on this is that as long as you get the Pertronix module installed correctly it won't go burning itself out. And if it did burn out, I'd be a lot more comfortable having a backup Pertronix module in the glovebox than a spare points and condenser. If my Pertronix unit failed, then swapping in a new one would be a lot faster than trying to convert everything back to points and condenser while I'm standing on the side of the road.

Part of the problem with the Pertronix module is that it's not very well documented. It took me a bit of thinking while not reading the instructions to figure out how the system actually works. Then, once I had a handle on how the circuit had to be designed internally, and what it needed externally to make it run reliably, I designed a new circuit to provide proper starting and running voltages. The Pertronix module is after all, a solid state device, and it has to have adequate Vin or it's just not going to work properly. I think that getting the running voltage wrong is the most likely way that end users cause one of these setups to malfunction, and preventing a low voltage operating condition is the best way to prevent one of these modules from failing. But then I only have a few months of experience on one unit. We'll see how it goes... <fingers crossed>

 

Thank you all for the input and comments. I'll check the connections, grounds and voltages that I can. The engine ran great when I parked in the garage, so there may be just something loose. I feared the timing chain concern, but I have replaced the original with double roller chain and new gears some time ago. Relatively few miles on the timing chain. It's a Pertonix Ignitor and a Pertronix flame thrower coil. My suspicions right now are in the ignition circuit, maybe the switch. Thanks again.

 

Best of luck. While you're at it, write down all those questions that people have been asking and let us know the answers. Otherwise we're playing a guessing game and there's no point in that.

 

Ditto.
The other build went full-nutso with Accel billet distributor signalling an MSD 6AL-2. I also do not carry points there.

 

I don't carry a spare set of points, but I do keep a .45 in the glovie.

 

Eh? A circuit?
Just tying to a full ignition feed is all that's necessary. Unfortunately it's been long enough since I've looked at a stock wiring diagram to remember if there's an ignition feed under the hood.

 

In Mass.??? How'd you get it past the metal detectors and crowds of whining Lefties at the border?

- Eric

 

Fer crying out loud, don't shoot your horse, call for a tow!

 

I'm surprised that anyone would give that advice, while admitting to not even being familiar with what's under the hood.

I know what's under my hood. My primary ignition feed in the run condition is 6 VDC. Although my coil requires 6 VDC the Pertronix units are 12 VDC devices that do not function reliably when Vin = 6 VDC. Period. Suffice it to say that everyone hooks up the unit according to their level of understanding and some installations fare better than others. That's why we see two types of people commenting on Pertronix units -- there are guys who say they work great and there are guys who say they are unreliable and fail. It's all about whether someone botched the installation or not.

 

For all of you with any interest and for those that tried to help me with this issue, here is the final results. First, there was nothing wrong with the Pertronix Ignitor or the Flame Thrower coil I am using. I had properly bypassed the ballast resistor, as suggested by Pertronix, to provide the Ignitor the full 12 volts it needs. However, I left the resistor in the circuit which goes to the + side of the coil. The short of the long story is the resistor gave up the ghost and dropped the voltage from 12 to almost zero at the coil. I checked the "run" voltage previously and decided it was the ignition switch (since it is a '68 item) that was not allowing the proper voltage in the "run" position of the switch. Nope, finally checked the voltage across the resistor and had an Aha! moment. Anyway, thanks again for all the suggestions and help.

 

If you bypassed the resistor, how could it have affected the current to the coil?

- Eric

 

The ballast resistor is between the ignition key and the coil. The 12 volts coming from the ignition key is dropped to approximately 9 volts (with a properly operating ballast resistor) at the positive side of the coil. Once the engine starts (ballast is jumped during start to provide the full twelve volts) and the ignition switch is now in the run position the coil would see about 9 volts. This was done as a protective measure for the stock coil. Some stock coils are even labeled that a ballast resistor must be used. The Pertronix coil has built in resistance and does not need the ballast resistor. So, when I bypassed the resistor I get a continuous 12 volts to the coil now. I could have purchased a new ballast resistor, and would have if I was using a stock coil, and got 9 volts to the coil. My ballast resistor failed and I wasn't getting enough voltage to keep the engine running after the start sequence.

 

I guess I am confused. If the ballast resister was bypassed, what would it matter if it failed. All you have to do is put both wires on one side of the resister and you will have effectively bypassed it. It won't matter if the resister is good or bad. You will have 12 volts to the coil and if you are concerned about looks, it will take a good eye to notice the wires are on the same side of the resister.

 

I don't believe your car came with a ballast resistor. It should have had a resistance wire. I'm confused.

 

+1. 1968 Olds had a resistance wire.

- Eric

 

redoldsman - sorry, I did bypass the resistor, but only after I discovered it wasn't working. I have it now wired as you suggested.
oldcutlass/MDchanic - ok, I'll take your word for it. This engine is in a Chevrolet street rod and has a ballast resistor. Sorry for all the confusion.

 

Ok makes sense now.

 

As the late great Paul Harvey used to say, "now we know the rest of the story". Glad you got it going.