Technical Pertronix Ignitor Bad?

I have developed a running issue and not sure what is the next step?....Currently running 350 Chevy...462 heads Comp Cams 280 Mag and Flat Top Pistons....I had converted this car from 4x2 Rochester 2gs to 3x2 about a year ago...I didn't know much about what had been previously done to the carbs but it ran ok other than a little rich at idle....About two weeks ago I installed a complete Pertronix distributor because I had left the key on by mistake and fried whatever brand electronic conversion that was in the old distributor (No Spark)....On the second trip out with the new unit I noticed a miss at low speed..The next trip out the miss was much worse and I wondered if it was going to quit running all together ..I thought perhaps it was the plug wires so I replaced them and the plugs.
Further investigation it seemed the front and rear carbs were not sealing completely all carbs had #59 jets and power valves were removed from all carbs to include the center. I purchased the Speedway kit and changed front and rear bases. Installed the the provided outer #55 and primary #56 jets cleaned and reinstalled all carbs...The miss and hesitation is still there...Very hard to start...Will not idle...And will only run at part throttle. Plenty of fuel shot from the accelerator pump....All plugs are black...Missfire seems to be on the right bank...and sometimes a backfire through the carb....Compression is 160 psi on all cylinders...Timing set at 16.. .Fuel delivery is good,,,Other than the rich idle this all started after the Pertronix install....Any Ideas? Thank You

 

Pull the coil wire from the distributor and hold it about 1/4" or 1/2" from a head bolt or something like that and crank it over. Should be a fat, hot bluish-white spark. The Pertronix Ignitor is basically an electronic switch and it basically either works, or it doesn't. Maybe they get flaky, I dunno.

They don't like high resistance in the primary circuit. Check the ohms between the negative battery post and the distributor breaker plate. No more than 0.2 ohms is allowed. You'll have to subtract the meter leads resistance from the displayed figure for an accurate determination.

 

I also noticed a very erratic tachometer after the install...I installed an Autometer signal filter that was no help actually made it worse..I replaced the SW unit that was in the car with one from Speedway....The replacement is not as bad...But not perfect..Thanks

 

That's been my experience. Had one go bad last year. The testing is simple, instructions all over the 'net. I suppose if the reluctor gap was slightly out of spec it could work erratically.

 

Did you use the Pertronix Flame thrower coil also? HRP

 

Yeah they take a shit in the diagnosis chart for it is replaced with a known good one.

 

Also they dont like solid core plug wires and some tachometers will screw with them . Disconnect the tach and try it , also make sure you have resister core wires .. good luck.

 

When in doubt about Pertronix your best help is from there Tec line. Those guys take Customer Service very serious. Not that you can't get help here as well as on line but they get right to the point with a few questions about things you may have over looked. Are you sure the coil you have is the correct one for the unit you bought? This is a very common issue. Pertronix Tec phone #909-599-5955

 

This is key!

 

I just got off the phone with Pertronix...According to the tech..The unit either works or it doesn't...He mentioned possibly the distributor not being properly grounded?...It almost seems like I have a huge vacuum leak?....I've never had a intake manifold start leaking vacuum after it was installed...And that has been a few dozen over the years...PCV is new and manifold is an Edelbrock 357...That was purchased new...I plugged the PCV port at carb and that made no difference...Thanks to all

 

This is something to check. Peeps sometimes remove the small, uninsulated braided copper wire that grounds the breaker plate on some distributors when they ditch the points. Bad Idea.

The distributor housing needs to "see" a clean, low resistance electrical connection where it mates to the block. Paint will interfere with this. Could try using a jumper cable or heavy wire on the housing connected to the battery ground terminal, but you should already know it's OK if you checked ohms resistance as previously described.

Maybe you do, a good diagnostic is the vacuum test. A stockish motor in good shape in good tune should pull 19" to 21" steady needle on a mechanic's vacuum gauge at factory idle RPM at factory ignition timing spec. There is a correction factor applied for altitude but if an engine won't pull the full vacuum with a steady needle, find out why, because it won't run right and can't be made to run right.

 

This kind of sounds like a Timing Chain going away. Being you know very little about the motor I'd do a manual check of chain slack. Turn motor by hand till pointer is at T.D.C. and cap off the Dist. Now rotate crank opposite direction and see how far it goes before the rotor begins to move. Being it appears everything else is correct but it just don't run right and it's the one thing you never look at, rule it out.

 

Another little detail to check off... is the distributor engage properly and seated against the intake, AND is it moving around on you? I ask because I chased a problem a few years ago that came down to the cheap chrome distributor clamp that came on the engine was made of a soft metal that would deform and not hold the dizzy in one spot. My timing was moving around after driving the car. A guy gifted me a genuine GM spring steel hold-down and that dizzy never moved again.

Gotta56forme/Scott

 

Leaving the key on cooks the coil as well.
The problem started when you left Key on.

 

Yes, they are.

 

Not sure which was the culprit or possibly all the above?...I changed the intake gaskets/Coil/also reset the carb floats that were slightly off....Running fine now and plugs look good...Thanks to all for the help.

 

Glad you got it resolved! I’d put money on it being the coil. I have yet to see someone complain about a Petronix unit and have it not be a bad/wrong coil.

 

I use their coil and kept the ballast resistor too. Not a problem in 7 years on my old Y-Block..

 

Glad you found it. Several yrs ago my son had a 40 coupe with a small block and pertronics. He would drive it and it would start missing and quit. Let it sit and it was good to go again then repeat the issue when warmed up. He let it cool off and came over. I changed the coil and end of problem.

 

Thank you for updating the thread when you got it resolved.

 

The Pertronix distributor uses the Ignitor II?

What coil were you using and/or what was the primary winding resistance?

 

I was using the 1.5 ohm Pertronix Flame Thrower coil....What lead me to believe that the distributor was at fault was I was having intermittent miss fires in the right bank exhaust...I thought could there be a possibility of it somehow firing late after the exhaust valve had opened...The first time on the road with the new distributor it seemed to run fine..Next time out it had a miss..Thought perhaps the wires since they were removed and installed on a new cap provided .Problem was worse the 3rd trip...It is the D104600 (Stock Look)..

 

OK. I missed the fact in the first post you're actually running a Pertronix distributor.

The Ignitor II and III need a low 0.6 ohm coil iirc. Using a low resistance coil is a dependable, proven way to burn up the Ignitor I module. It looks like running in the other direction isn't a whole lot better.