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1961 390 no spark pertronix

Started by 61Tom62, December 29, 2020, 01:16:03 AM

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61Tom62

Hello everyone, I'm new here with my recent purchase of a sweet 1961 series 62 coupe. I was tinkering around with the carb when the car lost spark. I decided it was time to swap in a pertronix. I installed a pertronix ignitor II, a relay kit p/n 2001, new plugs, wires, and coil. Still no spark. The relay kit says to use the resistance wire, which is how I have it wired up. I have power to the relay, to the coil, and at the resistance wire, but no spark. I'm not sure about this yellow wire which was on the old coil. Any help would be greatly appreciated on my first GM vehicle in my Mopar fleet!
Ignitor:
     Red to coil +
     Black to coil -
Relay kit 2001
     Red to battery +
     Purple to resistance wire (?)
     Orange coil +
     Black to firewall ground

TJ Hopland

The + coil terminal would have typically had 2 wires on it.   One was the resistor wire more or less coming from the key.   The other goes to the I terminal on the starter solenoid.  This becomes live when the starter is operating.  The idea was it was a fairly direct and shorter route to the coil that also bypassed the resistor to give the coil the most power possible during cranking.     

I don't know a 61 specifically but maybe the resistor wire isn't on during cranking?  Its expecting that other wire from the starter so maybe hooking that back up will do it?    Hook it too the purple wire with the resistor wire. 

Also verify the distributor is actually turning.  Could have had something gone wrong and its not turning for some reason.  If it is turning and you have verified its got power when on and during cranking then check the magnet gaps.   
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

Bobby B

Tom,
Hi. First off I would've investigated the source of your initial problem before swapping any new parts in, which obviously didn't correct your original no spark issue. What are you using a relay for? I've never used a relay before in an ignition system. And if I'm not mistaken, Pertronix coils/ignition get full 12V, and have to be wired accordingly. Was there a ballasted or non-ballasted coil in there originally, or an external ballast? If so, did one of those go bad initially? Did you purchase the wrong coil with the new system? Start from scratch and wring out your wiring first before purchasing and swapping any parts. The root of your problem wasn't addressed yet. And we need more specifics, like part numbers of your new components. Keep us posted.
                                                            Bobby
1947 Cadillac Series 62 Convertible Coupe
1968 Mustang Convertible
1973 Mustang Convertible
1969 Jaguar E-Type Roadster
1971 Datsun 240Z
1979 H-D FLH

dadscad

Tom, the resistance wire, the one with the braided covering, going to the coil will have about 9 or so volts while the engine is running, and 7 or so volts when not. The yellow wire supplies battery cranking voltage to boost spark at start up only. Check the system static voltage on the resistance wire at the coil. Be sure it is high enough to pull in the relay contacts. Relays have a volt range they will function with. If the resistance wire doesn't supply that range of voltage the relay will not send current to the coil, thus no spark. HTH
Enjoy The Ride,
David Thomas CLC #14765
1963 Coupe deVille

Jamurray

It may be a little late for this suggestion, but when your Cadillac wouldn't start with its stock ignition system, i.e. points & capacitor, it's probably best to get running with its stock equipment first before you install something different. I once tore apart half the engine in my '70 DeVille, before I discovered, after an innocent conversation with Petronix, that the Petronix I'd installed years before was my problem.


35-709

#5
The '61 points ignition system has a resistor wire - no ballast resistor.  That resistor wire should not be in the system with a Pertronix, there should be 12 volts directly to the coil at all times when the ignition is on.  The resistor wire begins at the engine side of the firewall connecting to the coil, and on the interior side of the firewall the 12 volt ignition wire that connects to the resistor wire is a pink 12 gauge wire that comes from the ignition switch.  Connect to this wire for your 12 volts to the coil, bypassing the resistor wire which should no longer be any part of the circuit --- remove completely if you desire.  A Pertronix equipped engine WILL USUALLY run using the resistor wire but at a reduced functionality, don't use it.  The wire from the starter to the coil that comes into play only when the ignition switch is in the "start" position is also superfluous and may also be removed.

I too have no idea what relay it might be that you are using or for what purpose.  I also agree that your no spark problem should have been resolved before adding the Pertronix.
       
1935 Cadillac Sedan resto-mod "Big Red"
1973 Cadillac Caribou - Sold - but still in the family
1950 Jaguar Mark V Saloon resto-mod - Sold
1942 Cadillac 6269 - Sold
1968 Pontiac Bonneville Convertible - Sold
1950 Packard 2dr. Club Sedan
1935 Glenn Pray - Auburn Boattail Speedster, Gen. 2

dadscad


Ignitor:
     Red to coil +
     Black to coil -
Relay kit 2001
     Red to battery +
     Purple to resistance wire (?)
     Orange coil +
     Black to firewall ground
[/quote]

Looking at the listed connections in the original post,  it appears that the relay is used to switch a direct battery connection to the coil/igniter by using the ignition resistor wire to trigger the relay. HTH
Enjoy The Ride,
David Thomas CLC #14765
1963 Coupe deVille

Bobby B

Quote from: dadscad on December 29, 2020, 08:24:49 PM
Looking at the listed connections in the original post,  it appears that the relay is used to switch a direct battery connection to the coil/igniter by using the ignition resistor wire to trigger the relay.

Which makes absolutely no sense......
                       Bobby
1947 Cadillac Series 62 Convertible Coupe
1968 Mustang Convertible
1973 Mustang Convertible
1969 Jaguar E-Type Roadster
1971 Datsun 240Z
1979 H-D FLH

61Tom62

Thank you everyone for your replies. I know full well I should have troubleshot the issue before putting the neato parts I bought, so I accept my scoldings for doing something I dang well know better than. So I've removed the pertronix relay kit (p/n 2001 -ignition power relay kit-). I cut the braided resistance wire at the distributor side and at the ignition key side. I spliced in a new wire to the pink 12ga on the ignition. That new wire now is on the coil + with the red pertronix ignitor wire, the black ignitor wire is on the coil -. I verified 12 volts at the battery, and on the coil with key on. The voltage drops to 8 when cranking but maintains. Still no spark from the distributor. The cap and rotor appear to be in decent condition but are old...would you recommend I change those out as well? I even added an extra ground via alligator clips to the distributor housing to make sure it had a good ground other than the existing one inside. Far as I can tell, the magnet wheel never contacts the ignitor nor pulls away farther than the desired .060". I figured that relay kit would allow me to keep the resistance wire without messing with the harness, should have saved the $40 and spent the 5 min running a new wire...I guess there's also the possibility that I have a bunk ignitor module as someone pointed out happened to them... Someone asked for part numbers, the ignitor two kit is 91181. I appreciate you guys replying, anymore would be greatly appreciated!!!

Bobby B

#9
Quote from: 61Tom62 on December 30, 2020, 12:33:42 AM
The voltage drops to 8 when cranking but maintains.....

Then something's wrong. The only time you should see 8V is when RUNNING on an original points set-up either by use of a ballast resistor or a ballasted coil to extend the life of your points. The points set-up still got a 12V shot of juice directly from your battery ( usually via the starter solenoid ) when cranking to assist in starting. I'm not saying that's your problem, but nowhere in your system now, should 8V be present at the coil, before OR after, if you verified 12V before cranking. Bypass the + wire now going to your coil and run a jumper directly off your battery with an inline switch directly to the coil while cranking, so you can shut the car down when needed after it's running.  A non-ballasted coil should be 3 ohms and a ballasted coil should be 1.5 ohms. If you're measuring 12V at the coil before cranking, but 8V when cranking, either you still have resistance in your coil + feed coming from a resistance wire or something's not grounded properly causing a voltage drop. Running directly off the battery should give you the answer because at least you know there's nothing else between the battery 12V+ feed  and the coil terminal. Use the switch as an on/off switch. A PO might have done something hokey that you aren't aware of, so go direct and try that first.
       Bobby
1947 Cadillac Series 62 Convertible Coupe
1968 Mustang Convertible
1973 Mustang Convertible
1969 Jaguar E-Type Roadster
1971 Datsun 240Z
1979 H-D FLH

dadscad

The battery post cranking voltage should be at least 10 volts for a good battery.  Best case scenario voltage at the coil would be equal to the battery post voltage. Like Bobby said, having 8 volts at the coil while cranking indicates resistance between the battery posts and the coil positive connection or poor grounds in the circuit. Check and clean all connections from the battery positive to the coil, including all ground points, frame to battery, frame to starter bolt, firewall to both heads, etc. Check the carbon button in the top of the distributor cap, be sure the rotor tab is making good contact with it. HTH
Enjoy The Ride,
David Thomas CLC #14765
1963 Coupe deVille

TJ Hopland

8 volts does seem a little on the low side during cranking.   Most automotive electronics are going to get flaky below 9 so unless they designed that module to expect especially low voltages that may be your issue.   Maybe try another battery or have it tested.   You could also try adding a ground engine to battery with half of a set of jumper cables.   If your battery tests good maybe your starter is on its way out and drawing too much.      For testing I suppose you could try and rig up another 12v source.    Hook that to the relay kit wire that went to the battery.   That way you will know the ignition is getting a 12v even if the starter is dragging things down much lower. 

Would that have caused the original problem?   I don't really think so,  that low could make a weak and erratic spark but I don't think would be a no spark sort of thing.   

That relay kit should be fine and its purpose is just how and why it was used here,  he didn't want to try and remove the resistor and didn't want to put any extra load on the original wiring.  I'm really amazed at how many people commented that that wasn't a good idea and didn't make sense.   A good relay will have 2 different coil ratings,  a pull in and a hold.   It takes a lot more power to pull in than to hold.   For this application it would not surprise me if the pull in is around 9v but it will hold with half that so again kinda ideal for this setup.

For your voltage testing are you working with an assistant that is turning the key while you are under the hood monitoring things?  Or do you have your meter(s) setup so you can see them while turning the key?   Just wondering if there could be any flaws in your testing procedure that may be confusing the results.   

Not that understanding this aspect is going to help this guy get running but the resistor in an ignition system isn't just a simple flat voltage reducer, its being used as a current limiting device which is kinda dynamic just like the coil ends up being.   I don't know of any good videos explaining how they work in an ignition system but I did find this video with an LED.   An LED has different properties among them being more constant than an ignition system but he explains it reasonably well and shows whats happening with the 2 meters.    IF you just think of the coil as the LED it still kinda works.   Its one of those concepts that seems like its simple but is actually pretty complex but still downright simple at the same time.  https://www.youtube.com/watch?v=81zNcctopBI 
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

Bobby B

Quote from: TJ Hopland on December 30, 2020, 11:15:18 AM
That relay kit should be fine and its purpose is just how and why it was used here,  he didn't want to try and remove the resistor and didn't want to put any extra load on the original wiring.  I'm really amazed at how many people commented that that wasn't a good idea and didn't make sense.   A good relay will have 2 different coil ratings,  a pull in and a hold.   It takes a lot more power to pull in than to hold.   For this application it would not surprise me if the pull in is around 9v but it will hold with half that so again kinda ideal for this setup.
TJ,
  Adding a relay for something of such a low current draw is a waste of time, money, and only complicates matters due to the fact that there's one more thing in the loop that could go wrong. And relay coils which draw next to nothing that have a poor ground or feed, WILL Chatter and not pull in. I've seen it happen many times, mostly with retrofitted ECU's or poor grounding where multiple devices are fighting for their grounds to operate. They do need the proper voltage, even though low current, to operate correctly. Any company will sell you a relay, but sometimes it really isn't needed. If your ignition switch is overloaded and starting to burn up at the terminals, then maybe it's a good idea. If your modern halogen headlights are burning up your antiquated lighting switch, then also a good idea. But for tapping off an existing coil circuit that doesn't draw that much in the first place, it's just more added confusion to me. I wire a lot of cars, mostly from scratch, and lately quite a few High HP resto-mods loaded with all modern day options. This is a situation where relays are your best friend and are a must to keep everything neat and running properly. Cooling fans, FI Fuel pumps, AC, Headlights, Horns, etc. are all high current items that would take a toll on any switch by running full current thru it. Here's where Relays are your friend by being cost effective and time saving. Your payoff is the end result being a neat, professional job that's easy to trouble shoot should a problem arise, and no callbacks with issues.
                                  Bobby
1947 Cadillac Series 62 Convertible Coupe
1968 Mustang Convertible
1973 Mustang Convertible
1969 Jaguar E-Type Roadster
1971 Datsun 240Z
1979 H-D FLH

61Tom62

Hey everyone! So I tested the resistance in the battery cables, changed them out and got proper voltage everywhere. Then I got a single spark. After carefully watching the magnet wheel for the ignitor, I noticed there was a wobble causing the magnet to rise too far from the module. A little careful bending and the car fired right up. I guess that .010" minimum on the downward slope is critical. Thank you for your replies and helping me out, I greatly appreciate it! Happy new year guys.

dadscad

Thanks for following up with the found solution.

Happy New Year!
Enjoy The Ride,
David Thomas CLC #14765
1963 Coupe deVille

savemy67

Quote from: 61Tom62 on January 02, 2021, 03:28:07 PM
I guess that .010" minimum on the downward slope is critical.

Hello Tom,

Whether inverse square or inverse cube, suffice it to say there is a relationship between magnetic force and distance, such that the greater the distance, the weaker the magnetism.

Both points type and Hall effect type triggering systems depend on an adjusted distance (gap) for proper operation.  Having never installed a PerTronix system, how is that distance adjusted on a PerTronix system?  Can the sensor be moved closer to, and further from, the wheel?

Thanks for posting your follow-up.

Respectfully submitted,

Christopher Winter
Christopher Winter
1967 Sedan DeVille hardtop