Pertronix III & Flame Thrower III Installed
Hi Guys,

I just finished installing the pertronix ignitor III and flame thrower III coil on my 1969 mach 1. Installation was pretty easy. Tuff part was running 12v from my ignition switch to coil, obviously disconnecting the ballast resistor wire through the tach to coil. Tach didn't work right so wasn't that concerned about disconnecting it. One day I'll get it converted. I started with my original coil but the timing was going out of wack.

I ended up ordering and installing the coil afterwards and that made the timing bettter but still not right. With my points, the car ran fine on 7 degrees BTDC. After the intallation the timing went to about 20 degrees. Not sure how that happened but I adjusted it back down. Timing seems to slip every few seconds. I can see it jump with the timing light. I'm not sure what it is. I did notice on the pertronix web site that they recommend stranded plug wires while mine are standard stock ones. I'm not sure if stock wires are solid core or stranded. I can't imagine this being the reason for the eratic timing. Any advice would be appreciated.
The stock spark plug wires are not a solid core wire. They are some type of carbon core. I'm not certain what is meant by a stranded core spark plug wire. Maybe just terminology and that is the same as a spiral core wire. For the money you cannot beat MSD Super Conductor spark plug wires. They are a spiral wound solid wire core. If you go that route also get MSD's Pro Clamps to hold them in place. Don't waste your money on MSD's Street Fire stuff.

As far as the Ignitor III installation, its best to replace the entire distributor with Fords. Typically with Ford points distributors as the distributor ages and wears the dwell starts to become unstable. Eventually the engine will misfire when the vacuum advance increases the timing. I've experienced it. If your distributor is worn it may be contributing to the timing variation.

Happy to hear the install went well. I'm just not a fan of Pertronix. No reflection on their products since I have never used them. Something about Petronix never set right with me. One of the reasons being its marketed as a simple upgrade and I don't see how they are much more simple than the others. Also, in many cases the entire distributor should be replaced.

Actually the wires are autolite professional series but I don't think those are solid core. My distributor works fine with the points system. Engine ran smooth with them but I did get stuck once from the point gap.
If your distributor was in good condition then it's fine to install a Pertronix system.

What usually occurs with stock Ford points distributors as the breaker plate wears is when the vacuum advance moves it the point gap increases and thus the dwell decrease. It eventually gets bad enough so that the engine starts to misfire when the vacuum advance moves the breaker plate to advance the timing. It's only after the engine starts misfiring when people realize something is wrong.

I'm sure you are right, the Autolite professional series spark plug wires are not a solid core wire. When you select a solid core wire it needs to be a spiral wound core to eliminate any RFI. (RFI, I think that's correct)?

I'm thinking my problem may be the engine ground. I get 1.5 ohms between the pertronix breaker plate ground wire and negative of battery. Same with the engine to battery. I can get the car to run smooth if i advance the timing to about 12 degrees but i get pinging when i floor the pedal. With the points system the car ran fine at 7 degrees.
1-1/2 ohms doesn't sound too bad. Try narrowing it down to a cable or a connection. Might just be a poor connection.

You can try temporarily adding a ground jumper wire direct to the battery negative terminal to the distributor housing and see if there is a difference.

How far can you run the base timing, 8, 10 deg BTDC? With timing your getting into an area where most people run as much base timing and mechanical advance as they can then scale back and often eliminate the vacuum advance timing to stop pinging.

Have you tried setting the timing at 10 deg BTDC and disconnect the vacuum advance to see if it pings?

There was such a base timing difference 7 to 20 deg BTDC between the original points and the Pertronix. The relationship between the distributor rotor tip and the contacts on the dist cap changed. I wonder if that has any affect?

I still wonder about the condition of the old distributor. (Sorry to bring that up again).

I think my leads on the voltmeter gave me bad readings. I originally used probes and now tried using alligator clips and got .2 ohms from distributor ground to batter. Also from engine ground cable to battery. I'll keep tshooting before thinking its the distributor. What bothers me is that the distributor is perfectly fine with points and condenser.
Is guess it's always possible there is something wrong with the Pertronix unit or coil. It's strange the engine runs smoother as the base timing is advanced and doesn't run well with the base timing close to stock

I wonder if anybody else has experienced that large of a base timing difference after installing a Pertronix unit. I'd be inclined to give Petronix a call and see if they have any input.

With the base timing change I am still curious if the changed rotor to cap contact relation has any affect.

After looking at the distributor cap closely I noticed the contacts had some corrosion so I cleaned them and seems like that fixed the problem. Took if for a couple of rides and engine runs smooth at 7 degrees btdc which is where the car always ran good. So I'm happy about that and on to the next isue to fix. When I honk the horns my tach needle moves. Go figure. Fix one break two.
Good to hear. I may be off base but I am thinking since the timing changed so much after installing the Pertronix, moving the distributor housing to reset the timing repositioned the rotor tip in relation to the contacts on the dist cap when the spark occurs. This might have increased air gap between the rotor tip and contact on the dist cap. That plus corrosion and the issue cropped up. That large timing change is still a bit odd to me.

It sounds like its ready for a new distributor cap and rotor. However, check the terminals on the cap occasionally see if they corrode very quickly.

I thought your tach was disconnected to install the Pertronix? If so the horns should have no affect.


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