Pertronix users question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**TBONE1964** · 02-25-2020, 10:31 PM

Hello all,

Any of you out there running Pertronix with stock tachs?

Sold a 6 cyl factory tach to a customer and he is concerned as well as myself as if there an issue. I think the pulse to negative side of coil should be the same???

Thank you I’m advance for any knowledge for this.

Take care,
Tom

**'68OrangeSunshine** · 02-25-2020, 11:28 PM

I had a Pertronix Ignitor II on the L6 292 In my '68 C/10 Stepside. I run an AutoMeter aftermarket tach. I never had a tach problem.
My buddy has a BBF 429 in a '72 F-250 longbed. He installed the Ignitor III. His tach wouldn't work. He called their Tech Rep. The guy said, if you want a tach go back to an Ignitor II. Or run a mechanical tach.
Ignitor 3 is some kind of multi-spark discharge, like an MSD.
The issue I had with Pertronix is that it burned out after 7 years. Ignition would kill above 3500 RPM -- usually on the freeway -- with the engine cold cranking in gear at 65 MPH --On/Off with the key and it would pop start at 55 MPH -- usually p!ssing off the guy behind you.
I called the tech line. They said to send the module in. I did, and never heard back from them. I went back to points for a year, then got GM type HEI.
I now run a regular HEI. Again no problems with my aftermarket tach.

Old_Gold · 02-25-2020, 11:50 PM

Hey Tom, I have a pertronix II on my 350. I'm using the negative terminal on the coil to feed the tach on my efi controller, works great!

Jim

**davischevy** · 02-26-2020, 12:00 AM

I have several. No problem.

**70cst** · 02-26-2020, 01:08 AM

I have mine in for years with no issues - 402BB

**Already Gone** · 02-26-2020, 04:58 AM

I have an Igniter11 and their matching coil on my 350. and my tach works but is always 5/700 RPMs higher than it should be for a given speed. I called Petronix and they told me to get a certain resistor which I did and put it in the line and nothing changed. I sure would like to get the tach working as it should or at least within 200 or so RPMs of where it should be.

racerop · 02-26-2020, 07:39 AM

Quote:

Originally Posted by Already Gone

I have an Igniter11 and their matching coil on my 350. and my tach works but is always 5/700 RPMs higher than it should be for a given speed. I called Petronix and they told me to get a certain resistor which I did and put it in the line and nothing changed. I sure would like to get the tach working as it should or at least within 200 or so RPMs of where it should be.

I would think a right sized capacitor
would lower your rpm reading to the correct
range maybe a coil/capacitor in parallel
before the tachometer

**Already Gone** · 02-26-2020, 08:17 AM

Quote:

Originally Posted by racerop

I would think a right sized capacitor
would lower your rpm reading to the correct
range maybe a coil/capacitor in parallel
before the tachometer

You lost me at capacitor. What is that and where could I get one..

**davischevy** · 02-26-2020, 11:23 AM

Quote:

Originally Posted by Already Gone

I have an Igniter11 and their matching coil on my 350. and my tach works but is always 5/700 RPMs higher than it should be for a given speed. I called Petronix and they told me to get a certain resistor which I did and put it in the line and nothing changed. I sure would like to get the tach working as it should or at least within 200 or so RPMs of where it should be.

I'm sure you would already have noticed if yours was bent, but my son in laws reads fast. Apparently when I detailed it I bent the needle.

custom10nut · 02-26-2020, 06:38 PM

I have the Mallory version of this, and have had it in for about 20 years now.
I’ve not had any issues with it interfering with the Factory Tach, in fact I just replaced the original tach and the new one reads very close to actual RPM ( I hooked up my Multi Meter while I was dialing it in).
Gone are the days of having to use a matchbook to adjust the points

That and the Tach works as it should, what ore could I ask?

**TBONE1964** · 02-26-2020, 07:28 PM

Thanks guys for all the help. I hate to see people fry these tachs because of lack of knowledge.

Appreciate it,
Tom

**Already Gone** · 02-26-2020, 07:50 PM

Quote:

Originally Posted by custom10nut

I have the Mallory version of this, and have had it in for about 20 years now.
I’ve not had any issues with it interfering with the Factory Tach, in fact I just replaced the original tach and the new one reads very close to actual RPM ( I hooked up my Multi Meter while I was dialing it in).
Gone are the days of having to use a matchbook to adjust the points

That and the Tach works as it should, what ore could I ask?

Yes, I believe my tach is an original. If I knew for sure that buying a new one would cure my problem I wouldn't hesitate to get one.

**dmjlambert** · 02-26-2020, 08:41 PM

Is there an adjustment?

**'68OrangeSunshine** · 02-26-2020, 10:57 PM

Quote:

Originally Posted by custom10nut

Gone are the days of having to use a matchbook to adjust the points

Real hard to find a crisp new matchbook nowdays.

**Bob B.** · 02-27-2020, 12:52 AM

Have a Pertronix Igniter on my GMC V-6, using a repro OEM style tach I had recalibrated for 6 cylinders. No issues, it has worked for years.

**jmader** · 03-09-2020, 09:08 AM

I tested my setup yesterday and my tach stayed around 700 RPM at all times. I don’t remember if I have the igniter or igniter II. I didn’t have time to mess with it any ideas what could be causing it?

**TBONE1964** · 03-09-2020, 03:46 PM

Quote:

Originally Posted by jmader

I tested my setup yesterday and my tach stayed around 700 RPM at all times. I don’t remember if I have the igniter or igniter II. I didn’t have time to mess with it any ideas what could be causing it?

Does it matter if you cycle key from off to on?. Does the tach rest at zero rpm with key on or off or always stays at 700 rpm?
Posted via Mobile Device

**jmader** · 03-09-2020, 05:01 PM

Quote:

Originally Posted by TBONE1964

Does it matter if you cycle key from off to on?. Does the tach rest at zero rpm with key on or off or always stays at 700 rpm?
Posted via Mobile Device

It resets to zero when I turn the key off. I didn’t mess with it too much because I don’t have an exhaust yet but it’s being installed tomorrow so I should be able to look into it further then.

02-25-2020, 10:31 PM	#1
TBONE1964 Cluster King Join Date: Nov 2012 Location: Junction City, OR Posts: 5,263	Pertronix users question Hello all, Any of you out there running Pertronix with stock tachs? Sold a 6 cyl factory tach to a customer and he is concerned as well as myself as if there an issue. I think the pulse to negative side of coil should be the same??? Thank you I’m advance for any knowledge for this. Take care, Tom __________________ Contact me on all of your gauge cluster needs. I specialize in restoration, repair and parts sales for 67-72 Chevy and GMC trucks. email me at tbonegarris@yahoo.com I am also a dealer for Counterpart for gauge cluster parts only. Also see my facebook page, CG&C

02-25-2020, 11:28 PM	#2
'68OrangeSunshine Senior Member Join Date: Feb 2002 Location: Tucson, AZ USA Posts: 7,436	Re: Pertronix users question I had a Pertronix Ignitor II on the L6 292 In my '68 C/10 Stepside. I run an AutoMeter aftermarket tach. I never had a tach problem. My buddy has a BBF 429 in a '72 F-250 longbed. He installed the Ignitor III. His tach wouldn't work. He called their Tech Rep. The guy said, if you want a tach go back to an Ignitor II. Or run a mechanical tach. Ignitor 3 is some kind of multi-spark discharge, like an MSD. The issue I had with Pertronix is that it burned out after 7 years. Ignition would kill above 3500 RPM -- usually on the freeway -- with the engine cold cranking in gear at 65 MPH --On/Off with the key and it would pop start at 55 MPH -- usually p!ssing off the guy behind you. I called the tech line. They said to send the module in. I did, and never heard back from them. I went back to points for a year, then got GM type HEI. I now run a regular HEI. Again no problems with my aftermarket tach. __________________ Every 25 years I like to rebuild that 292, whether it needs it or not.

02-25-2020, 11:50 PM	#3
Old_Gold Registered User Join Date: Jan 2017 Location: Mason City, IA Posts: 157	Re: Pertronix users question Hey Tom, I have a pertronix II on my 350. I'm using the negative terminal on the coil to feed the tach on my efi controller, works great! Jim

02-26-2020, 12:00 AM	#4
davischevy Senior Member Join Date: Sep 2008 Location: Harrison, Arkansas Posts: 9,836	Re: Pertronix users question I have several. No problem. __________________ other Larry Build thread, Arkansas K10 https://67-72chevytrucks.com/vboard/...=755797&page=5 The ability to speak several languages is an asset, but the ability to keep your mouth shut in any language is priceless.

02-26-2020, 01:08 AM	#5
70cst Senior Member Join Date: Feb 2001 Location: New Madison, Ohio Posts: 21,373	Re: Pertronix users question I have mine in for years with no issues - 402BB __________________ A husband can be right...or...A husband can be happy. 67-72 Chevy and GMC Trucks...The Classic Truck for the Classic Folk. 1970 CST Two tone green, 402BB, 400 Automatic, Tach, Buckets, AC, AM-FM, Tilt, GM CB, GM 8 Tract, LWB, etc JOHN 17:3...The better side of "LIFE" Remember: Everyday is a good day...Some are just gooder!

02-26-2020, 04:58 AM	#6
Already Gone 70+ ( Old Skool Club ) Join Date: Nov 2003 Location: Saskatoon, Saskatchewan ,Canada Posts: 9,139	Re: Pertronix users question I have an Igniter11 and their matching coil on my 350. and my tach works but is always 5/700 RPMs higher than it should be for a given speed. I called Petronix and they told me to get a certain resistor which I did and put it in the line and nothing changed. I sure would like to get the tach working as it should or at least within 200 or so RPMs of where it should be. __________________ 1972 C10 Custom/Deluxe 613 Highlander 406/700R4 1999 White Tahoe LS 4x2 with Z56 Police Package 1992 K1500 GMC Suburban Members I have personally met: MusicMan70 - HeavyD - ChewyChevy67 - StingRay -71SWB4x4 - 67 Burb - DeadheadNM - too much stuff - bc65 - das601 " Circumsatances Do Not Change Responsibility " " The Sky is not the Limit, Your Mind is." Marilyn Monroe .. RIP Charlie Watts 1941 - 2021

02-26-2020, 06:38 PM	#10
custom10nut Registered User Join Date: Apr 2015 Location: East Tn (In the heart of the Smoky Mtns) Posts: 1,882	Re: Pertronix users question I have the Mallory version of this, and have had it in for about 20 years now. I’ve not had any issues with it interfering with the Factory Tach, in fact I just replaced the original tach and the new one reads very close to actual RPM ( I hooked up my Multi Meter while I was dialing it in). Gone are the days of having to use a matchbook to adjust the points That and the Tach works as it should, what ore could I ask?

02-26-2020, 07:28 PM	#11
TBONE1964 Cluster King Join Date: Nov 2012 Location: Junction City, OR Posts: 5,263	Re: Pertronix users question Thanks guys for all the help. I hate to see people fry these tachs because of lack of knowledge. Appreciate it, Tom __________________ Contact me on all of your gauge cluster needs. I specialize in restoration, repair and parts sales for 67-72 Chevy and GMC trucks. email me at tbonegarris@yahoo.com I am also a dealer for Counterpart for gauge cluster parts only. Also see my facebook page, CG&C

02-26-2020, 08:41 PM	#13
dmjlambert Senior Member Join Date: Apr 2016 Location: Cypress, TX Posts: 3,811	Re: Pertronix users question Is there an adjustment?

02-27-2020, 12:52 AM	#15
Bob B. Senior Member Join Date: Aug 2005 Location: Los Angeles Posts: 1,348	Re: Pertronix users question Have a Pertronix Igniter on my GMC V-6, using a repro OEM style tach I had recalibrated for 6 cylinders. No issues, it has worked for years. __________________ 1967 GMC CM-2500 Camper Cruiser, 351E V-6, NP 435 4 speed, Dana 60, and factory A/C. 2012 GMC K-3500 WT regular cab, 6.0L Vortec, 6L90.

03-09-2020, 09:08 AM	#16
jmader Senior Member Join Date: Aug 2013 Location: Grand Island, NE Posts: 1,483	Re: Pertronix users question I tested my setup yesterday and my tach stayed around 700 RPM at all times. I don’t remember if I have the igniter or igniter II. I didn’t have time to mess with it any ideas what could be causing it? __________________ 1949 Chevy 3100 Five Window 1964 Chevy C10 Lambrecht Auction project 1967 Chevy SWB K10 1967 GMC K15 Project Build thread- http://67-72chevytrucks.com/vboard/s...72#post6502772 1968 Chevy Anniversary K10 1991 K5 4" Lift 35's (the wife's toy)



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