While 130psi is toward the low side, it should run fine.  You also need to have the throttle wide open for the test.  If you don't, then the pressure will indicate lower than it should.  However, the compression pressure of one cylinder alone is not very meaningful.  What is the pressure of the others and how do they compare?



Lawrenceville, GA

That is the only plug that is misfiring and sooty. All the rest are tan in colour and are firing. I have replaced the plug, checked the spark plug wire, Distributor cap, Rotor.              All Good.

If you want to do it right, you need to check the rest to see how it compares and narrow down the possible causes.  If they all happen to be about 130psi, then compression probably is not the problem.  If the others are higher, then compression could have something to do with it.  The compression pressure of one cylinder is practically meaningless unless you have something to compare it against.



Lawrenceville, GA

How did you check the plug wire? Internal breaks that can cause intermittent problems are hard to find. I usually swap one from a good cylinder and run it for a while then recheck the plugs and see what each cylinder is doing, just a thought.

I installed the Petronix II and Flamethrower II coil this morning and will keep my original as a back up. As far as performance I can't tell the difference between the two or a good set of points adjusted with the proper dwell..

I just installed a 4th Flamethrower coil (epoxy filled) in the stock location without a resistor. It got hot, became hard to start and sputtered all the way home. It lasted 1 day. I put my original 59 year coil back in car as soon as I got home & runs fine.
So much for a HIGH PERFORMANCE COIL.  Its more like a NO PERFORMANCE COIL. I dont get it

I don't get it either, something isn't right but I have no idea what would cause that with yours.
I ran the original Pertronix and flame thrower coil without a resistor for two years and it was a used unit I got from a friend and he had it on his car for maybe five years before giving it to me. Thats why I just put in the Pertronix II and matching coil. I've only put about 50 miles on it so far but no problem yet.

Nat.  Without making me go back and read through all the posts, which Pertronix unit do you have; I, II, or III?  My experience has been that the Ignitor I requires a resistor while the II and III do not.  The Ignitor I also requires a 1½ ohm coil whereas the Ignitor II and III units requires coils with less resistance.  The factory coils will be in the 1½ ohm range.  If you have a factory resistor wire on the car in conjunction with another resistor, that could be a problem.  Likewise running a resistor wire along with a Ignitor II or III unit with the incorrect ohm coil.

Lorena, Texas (South of Waco)

Hey Ted
I am running the ignitor 1. I have the stock external resistor on the car. I followed the instructions on installation and have spoken to their tech support. The ignitor 1 and flamethrower 1, (1.5 ohm coil) they say to bypass the external resistor. If I run the flamethrower with an external resistor the coil is cooler but the performance is not great. I am currently running a mustard top coil with external resistor and the ignitor 1 and the car is running well. However this past week the #5 spark plug started to foul badly out of nowhere. It is a dry fluffy black soot. I replaced all the plugs. Changed the #5 plug wire, cap and rotor, and reset the timing at 10 degrees. The valve clearance was also checked and are spot on. The #5 plug is not fouling but is a bit darker than than the rest. The cylinder is running about 100 degrees cooler than all the other ones. The compression is about 125 lbs the others 150. Checking the vacuum it was reading 19 and steady needle. It is generally running rougher with a slightly erratic idle  and then strangely it will idle quite smoothly and then idle rough again. The exhaust smell is also bit stronger than usual. I hope this is not a ring issue or I will have park it.

Nat.  Have you checked that your car doesn’t have a 'hidden' resistor wire going to the coil?  Beyond that I’m clueless as to what your 'Pertronix specific' coil problem could be.
 
Regarding the lower compression check on the #5 cylinder, I’ll suggest doing a leak down test.  That will help to verify if you have a ring, exhaust valve, intake valve, or combination of these making for the lower compression.  Performing the leak down test on all cylinders will give you some good baseline numbers.

Lorena, Texas (South of Waco)

There is no additional hidden wire going to the coil. I have the red ignition wire joined to the red ignitor 1 wire and plugged into the bottom of the stock resistor. I have a black wire connected to the top of the resistor going to the negative side of the coil.


When I was using the flamethrower1 coil the I had red ignition wire joined to the red ignitor 1 wire and going direct to the + side of the coil and the black Ignitor wire connected to the negative side of the coil.

Do you know what the stock mustard top coil voltage output is?
Thanks Ted