jfryjfry
jfryjfry SuperDork
10/6/21 10:19 p.m.

I'll begin with where I'm at:

I have a 351w small block Ford that has no spark. I have a pertronix flame thrower 2 coil and ignition. 
 

 I have 12v constant to the coil (during run AND start positions of the ignition switch) and the pertronix ignition pos and neg go to the coil. 

these items require 12v and not a resisted 9v. 

I have a new battery (5 months old) fully charged (12.6v)

I am showing 10.6 v at the coil when I crank it  

I have .1 ohm resistance from the distributor baseplates and ignition plate to the neg term of the battery  

I currently have no spark  either at the plugs or off of the coil wire  

I have jumpered 12v directly to the coil with no change. 
 

the rotor and cap and wires seem to be in good shape and the rotor is turning  

 

a test light from the neg of the coil to the neg post on the battery just flickers when cranking  - it is not clear on and off's  

 

i thought it was either the coil or the ignition as that's all that's left so I bought new ones and swapped the coil and then the ignition with no change  

it ran before, although it would occasionally not start but would with starting fluid so I figured it might have been the fitech.  So I swapped out for a holley sniper and now have no spark. 
 

The ignition is separate from the fuel injection. 
 

I've gone over everything and reduced it to just a wire from pos battery to the coil, and the pertronix ignition to the pos and neg of the coil.

 

what can I test next???  Could it be some interference from the starter?

 

Javelin (Forum Supporter)
Javelin (Forum Supporter) MegaDork
10/6/21 10:50 p.m.

The pertronix pickup died. It's happening a lot lately. You aren't getting a signal from the distributor at all. You need a new one.

jfryjfry
jfryjfry SuperDork
10/6/21 11:54 p.m.

I thought so but tried a new one and same result.  Not saying it's not broken too but I'm not convinced.  
 

 

Javelin (Forum Supporter)
Javelin (Forum Supporter) MegaDork
10/7/21 1:26 a.m.

In reply to jfryjfry :

My dad builds crazy AMC motors for customers and had three bad ones in a row brand new earlier this year. 

Mr_Asa
Mr_Asa PowerDork
10/7/21 5:13 a.m.

If the Pertronix is bad you should be able to pick up the parts for a Duraspark II setup (Ford's late 70s-early 80s electronic ignition) for pretty cheap?

I run mine with a GM HEI ignition control module. 

jfryjfry
jfryjfry SuperDork
10/7/21 8:51 a.m.

In reply to Javelin (Forum Supporter) :

Well, that's encouraging (both sincerely and sarcastically....)

jfryjfry
jfryjfry SuperDork
10/7/21 8:52 a.m.

In reply to Mr_Asa :

I'll look into it.  I really want simplicity (which the pertronix is) and reliability (which it may not be)

jfryjfry
jfryjfry SuperDork
10/7/21 9:12 a.m.

Mr. Asa got me thinking and searching for alternatives and it looks like there are some affordable hei dostributor setups for the same price as the pertronix unit itself. 
 

But since you usually get what you pay for, I'm wondering if anyone has any suggestions on a good quality, affordable, nothing fancy (stock)  distributor. Likely hei. 
In case that's my issue....

SkinnyG (Forum Supporter)
SkinnyG (Forum Supporter) UberDork
10/7/21 9:30 a.m.

I'm sure adapting HEI isn't going to be that hard.

Or even going to the Ford Duraspark.

Replacement parts for those are cheap, everywhere, and easily replaceable when you're 300 miles north of Gimli Manitoba.

(The smart kids keep an extra module in the glove box.)

Robbie (Forum Supporter)
Robbie (Forum Supporter) MegaDork
10/7/21 9:30 a.m.

Can you manually 'fire' the coil just to make sure the whole system works? Like if you had points all you do is open them with the system powered and you should get a spark out of the coil. 

That may help implicate the pertronix. 

APEowner
APEowner SuperDork
10/7/21 10:02 a.m.

I wouldn't be the least bit surprised to find multiple bad Pertronix ignitions.  We run Pertronix systems in Formula Fords and I've had to buy multiples to get one good one.

My preferred budget  ignition for old school Ford V8s is the Duraspark.  If I'm not trying to preserve the old school look and I want maximum performance I use an MSD system.

Woody (Forum Supportum)
Woody (Forum Supportum) MegaDork
10/7/21 1:25 p.m.

Have you confirmed that the distributor shaft is actually turning?

Saron81
Saron81 HalfDork
10/7/21 1:29 p.m.

If you have 12v straight to the coil, and the Petronix is wired to the correct terminals on a known good coil, I don't see how it could be anything else other than the electronic pickup,  as long as the distributor is turning. Does it need to be setup with a certain air gap?

APEowner
APEowner SuperDork
10/7/21 1:49 p.m.
Woody (Forum Supportum) said:

Have you confirmed that the distributor shaft is actually turning?

That's a good thing to check!

Mr_Asa
Mr_Asa PowerDork
10/7/21 5:46 p.m.
jfryjfry said:

In reply to Mr_Asa :

I'll look into it.  I really want simplicity (which the pertronix is) and reliability (which it may not be)

Its a factory stock unit, my man.  Its as simple as the Pertronix is.  I've only kept the GM control unit as it is what I'm used to and I've got a couple spares in the glove box.

APEowner
APEowner SuperDork
10/7/21 6:05 p.m.
jfryjfry said:

Mr. Asa got me thinking and searching for alternatives and it looks like there are some affordable hei dostributor setups for the same price as the pertronix unit itself. 
 

But since you usually get what you pay for, I'm wondering if anyone has any suggestions on a good quality, affordable, nothing fancy (stock)  distributor. Likely hei. 
In case that's my issue....

I've had a couple of customers who've had the DUI distributors and been happy with them.  Davis Unified Ignition

Mr_Asa
Mr_Asa PowerDork
10/7/21 6:14 p.m.

In reply to APEowner :

I've also known a bunch of people that have gone with DUI, lots of good things to say.

jfryjfry
jfryjfry SuperDork
10/7/21 7:59 p.m.

Good to know about the dui stuff. 

good call on the distributor rotating and yes, fortunately it is  

 

I realized I might not have been checking the distributor for spark correctly - my gap might have been too big. 
 

so I put a lead in the neck of the coil right by the metal and manually triggering it, I got little sparks.  
 

so I hooked up the pertronix and checked while the motor was cranked but still just the lead in the coil neck and it sparked away.  
 

I put the coil lead wire on it to the distributor and nothing. 
 

now I checked again and it doesn't seem to be sparking.  Argh.  
 

im going to write down everything I'm doing and start over. 

Javelin (Forum Supporter)
Javelin (Forum Supporter) MegaDork
10/7/21 8:03 p.m.

In reply to jfryjfry :

I'm telling you it's bad...

Mr_Asa
Mr_Asa PowerDork
10/7/21 8:04 p.m.

The cheapest solution is to throw points and a condenser back into it to test.  Did you happen to hold onto them?

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
10/7/21 8:36 p.m.

I had problems with bad Pertronix units ten years ago.  Very finicky, to the point where I didn't see how it was an improvement over points.

 

I have heard that you can use points to switch an HEI module, and doing so would make the points last just about forever because they passed no real current, but I learned this long after my last points-equipped car, and experimenting on customer cars is generally considered to be poor form.

jfryjfry
jfryjfry SuperDork
10/7/21 11:08 p.m.

I think I have it....  apparently every time I tested the spark I had the signal wire to the new sniper hooked up.  Or at least it was touching the neg post.     I have it run through a piece of brake line as a shield but it holds the terminal right at the post. 
 

anyway, starting back at square one I started testing everything again.  But this time I made sure ONLY the pertronix was on the neg post.  And whoa! It fired up!   Just on the fuel in the body.  
 

I tested the now open signal wire from the sniper and it was shunted to ground  

So I re connected the signal wire to the coil and nada.  
 

disconnected it and it fired up!

 

so the sniper is grounding the signal wire instead of just reading it as the pertronix tries to open and shut it

 

maybe a software set-up issue but I doubt it.  I'll be calling them tomorrow!

APEowner
APEowner SuperDork
10/8/21 3:51 a.m.
jfryjfry said:

I think I have it....  apparently every time I tested the spark I had the signal wire to the new sniper hooked up.  Or at least it was touching the neg post.     I have it run through a piece of brake line as a shield but it holds the terminal right at the post. 
 

anyway, starting back at square one I started testing everything again.  But this time I made sure ONLY the pertronix was on the neg post.  And whoa! It fired up!   Just on the fuel in the body.  
 

I tested the now open signal wire from the sniper and it was shunted to ground  

So I re connected the signal wire to the tach and nada.  
 

disconnected it and it fired up!

 

so the sniper is grounding the signal wire instead of just reading it as the pertronix tries to open and shut it

 

maybe a software set-up issue but I doubt it.  I'll be calling them tomorrow!

Good job!

llysgennad
llysgennad Reader
10/8/21 1:35 p.m.

+1 on using D.U.I if you go to an HEI system. I started with a knockoff brand, and the gear was not right and completely destroyed the drive gear on the camshaft (AMC V8) within a couple thousand miles.

Good job finding the problem!

jfryjfry
jfryjfry SuperDork
10/9/21 6:14 p.m.

I'll look into those for sure.  
 

What I'm confused on is one guy at Holley  said that sniper won't work with pertronix.  Ignitions. But others online have had them working, at least the ignitor II.  The III is a multiple spark discharge and apparently won't work. 
 

so I called back to verify whether they really won't work with any snipers (in spite of others having success) or if it is a prob with the sniper unit seeing as thr yellow goes to ground and that would make ANY coil-based ignition not work, not just this pertronix set up. 
 

They said to send it in so I'm just going to send it in.  They also said to buy one of a few different distributor and ignition setups anywhere from $350-500-$700. ugh

 

 

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