Ignitor I / Flamethrower Coil / Resistor Wire - UPDATE: Won't Start

[Sacbill]

My recent problem is that the car will "die" at some point after achieving operating temperature.  After sitting for a bit (sometimes just a few minutes), the car can start.  It usually dies again after as little as 30 seconds or a few minutes.

My setup: 289 4-V, A/T, Ignitor I, and a Mallory coil.

After some discussion with other SFers, I decided to look at  the coil.  I measured the primary and secondary resistance of the Mallory coil against specs and it was 2x - 3x's higher than it was supposed to be.  (Measured at both room temp and operating temp).  This seemed to indicate that the coil could be the problem, since increased resistance would equal reduced voltage.

I bought the Pertronix Flamethrower (specs: 1.5ohm 40k-volt) for installation.  Reading the instructions, it says to remove / bypass the resistor wire in the system.  This got me to thinking...had I EVER bypassed the resistor wire in the whole time I've had the car?  I followed their directions for evaluating for a resistor wire by:
* running a jumper from the Neg terminal of the coil to a ground
* Connecting the Pos lead on the voltmeter to the pos terminal on the coil
* connecting the neg lead on the voltmeter to a ground
* turning the ignition to the "ON" position.
* "Anything less than 12 Volts indicates a resistance circuit"...I measured 6 Volts

So, it appears that the pink resistor wire IS in place, and, yes, a visual check shows it's still there in the harness.

I have to interject here and note how I have the Ignitor connected: The black (-) wire is connected to the Neg terminal on the coil, and the red (+) wire is connected to the Pos terminal on the coil.  Seeing this led me to look at Pertronix' recommended wiring for the Ignitor in such a system.  The directions indicate the red wire should be between the ignition switch and the resistor (which I interpret as needing to be spliced in with the pink wire at the ignition switch).  See Page 2 of Pertronix directions at this link.

So, it appears that I've been running both the Ignitor and the Mallory coil at less than 12Volts this whole time.  (Hmmm, could that have been a problem?  )

It appears that my next action is to bypass the pink resistor wire. From research on SF, it appears that I do the following:
* Use a 14ga wire
* Connect the wire at one end of the pink wire (ignition switch) and the other end of the pink wire (where it enters the modular plug at the firewall)
* Cut each end of the pink wire and wrap with tape to avoid potential shorting

My questions:
*Are these steps correct?
* Exactly which kind of splicing connection is recommended?  A butt-connecting splice?  Side splice?  Other?
* I see that the existing pink wire has black insulation around it ( I'm assuming this is a heat insulation).  Does the new wire need the same additional insulation?
* I am thinking that I can maintain my current Ignitor wiring (red lead at the pos post of the coil), because the resistor wire is eliminated.  Does that sound accurate?
* Am I missing anything else?

Thanks!

[Midlife]

As the current flows through the resistor wire, the wire heats up, increasing its resistivity.  The design is such that it reaches equilibrium by reducing the current by increasing resistivity until the two are balanced.

To effectively remove the resistor wire from the circuit, it is best to cut it about 1/2" to 1" from each end.  The severed wire (long section now completely disconnected) can be left in place without harm.  Remove 1/8-1/4" of insulation, and use a butt splice to 14-18 gauge wire.  You can only silver solder the resistor wire, so butt-splicing is the only way to go.  Use shrink tubing around each splice (one at end end, of course!).  The small remnant of pink resistor wire that is left over offers little in the way of resistance, so you now are effectively running full battery voltage to the coil.

For 1967/68, there is no other line that is only hot with the key in RUN position and cold in all other positions.  It would be nice to be able to splice another line to the coil and simply remove the existing line off of the coil. 

Good luck!

[Sacbill]

Thanks for the guidance, Randy.  I clipped the pink resistor wire as per your instruction and spliced in a 14ga wire.

A quick check of voltage in the ON switch position (as per Pertronix instruction above: jumper between neg post of coil and an engine ground.  Voltmeter on engine ground and pos post of coil) yielded a reading of 10 volts.  Not 12V, but better than the 6V I was getting before changing out the resistor wire.

So, I try firing up the car and I'm getting plenty of cranking, but it won't fire up.  It seems like I might be getting a bit of firing, but it won't stay on when the key is released from 'start' to the 'on' position.

Based on what I've read here on the forum, it would appear that I'm not getting voltage at the coil, but that seems odd since I did measure 10 as outlined above.  I'm not sure what to check next.  I assume it's possible the Ignitor fried, but I'm not sure how to test it.  Continuity across the pos and neg leads, maybe?

TIA for any suggestions!

[66benchcoupe]

Looks like you're on the right track.  One thing I'd recommend is checking your battery's resistance to ground.  With an ohm meter you should measure less than 1 ohm resistance to ground between the engine block and the negative post on the battery.

A few years ago I was driving to Sayre, PA in the rain and my wipers wouldn't work in my 5.0.  I measured resistance to ground and it was 40 ohms!  A quick cleanup of the neg battery post and terminal was all I needed to do to see where I was driving again.  Bad grounds are the source of most car electrical problems. . .

Robert

[cmayna]

Bill,
How about pulling the coil wire from the dizzy and ground it while cranking to see if you are getting spark to the dizzy.

[SAC69]

I know almost nothing about electrical systems but if you need to borrow a coil let me know.  I have a Mallory in the car now and an original yellow-top laying around too.

A total stab in the dark:  could this be related to a bad voltage regulator or does that only regulate the alternator-to-battery current flow?

[Horseplay]

As long as the grounds are good, this typically ends up being an electronic issue so I would look hard toward the Ignitor module. Electronics tend to show fault as they heat up so that fits fairly well here.

[Sacbill]

For 1967/68, there is no other line that is only hot with the key in RUN position and cold in all other positions.  It would be nice to be able to splice another line to the coil and simply remove the existing line off of the coil. 

Good luck!

This is curious since I spliced in awhile ago to the green w/red stripe wire coming from the ignition switch in order to provide 12-volt switched power to the choke. It's always worked. (Wire 904 on the schematic)

For what it's worth, the car is also running a single-wire alternator, so the typical regulator circuit isn't attached.

Sent from my Droid using Tapatalk

[Mach1Rider]

IIRC the grn/red wire was to the volt reg from the key, that is how the choke is getting poer now.

As for the no start, Did you happen to clip the brown wire?
This is what give power to the +coil side when cranking.
Try turning key to On and jump the starter sol to crank eng.
Does it run? yes, Then trace the brown wire from the sol back to coil + wire for connection.

[Midlife]

This is curious since I spliced in awhile ago to the green w/red stripe wire coming from the ignition switch in order to provide 12-volt switched power to the choke. It's always worked. (Wire 904 on the schematic)

For what it's worth, the car is also running a single-wire alternator, so the typical regulator circuit isn't attached.

Sent from my Droid using Tapatalk

I was speaking of what's on the engine side of the firewall.  For 67/68's, there is a green/red wire that is tied into the pink wire (usually at the ignition), but the configuration changes when one has a tach dash. 

Otherwise, good catch!

[DEL65]

Have you swapped out the Ingiter yet?

[Sacbill]

Have you swapped out the Ingiter yet?

Not yet, but I do have a new one here. That's why I was asking if anyone knows the test for a dead Ignitor. I'm thinking it might be a lack of continuity across the leads, unless someone knows of another test.

Tomorrow, I'm going to measure each unit and see what I get.

UPDATE: Just found this Pertronix Ignitor Test Schematic.  LINK HERE.  Will report back....

[DEL65]

OK let us know how it goes. If it's not the Ignitor, at least you'll have a spare.

[Horseplay]

Not yet, but I do have a new one here. That's why I was asking if anyone knows the test for a dead Ignitor. I'm thinking it might be a lack of continuity across the leads, unless someone knows of another test.

Tomorrow, I'm going to measure each unit and see what I get.

Sent from my Droid using Tapatalk

Depending upon how it failed or faults it may not be that easily tested. I've never had one so I can't say for sure. As long as you have determined the circuit is not improperly grounding out or in some other way probable to damage a new unit, hook it up and see how it goes. My money is still on it being your culprit.

[Sacbill]

Hi, folks!  I appreciate everyone's help!!!  Here's what I've done so far:

1.  Measured resistance on the primary and secondary coil circuits.  They're both in spec.

2.  Tested the existing ignitor as per the Pertronix test procedure (see LINK above).  It operated as intended.  (Tested the brand new Ignitor with the same results.)

3.  Inspected the terminals in the cap and they looked a bit charred up.  I replaced the cap and rotor with new ones.

4. 

66benchcoupe: With an ohm meter you should measure less than 1 ohm resistance to ground between the engine block and the negative post on the battery.

This looks okay.  I'm measuring 0.3 ohm resistance

5.  Tried starting.  No can do.  It cranks and sounds like it's firing right up, but dies as soon as I release the key from the start position.

6.

cmayna: How about pulling the coil wire from the dizzy and ground it while cranking to see if you are getting spark to the dizzy

Checked this and I am getting a spark from the coil wire end as the car cranks.

7.

SAC69: A total stab in the dark:  could this be related to a bad voltage regulator or does that only regulate the alternator-to-battery current flow?

Not sure how this applies because I think the regulator just maintains 12v once the car's running.  Am I thinking of the same part as you?  Is it possible that the wiring inside could crap out, causing there to be no "steady" voltage signal going to the solenoid? 

8.

Mach1Rider: Try turning key to On and jump the starter sol to crank eng.  Does it run? yes, Then trace the brown wire from the sol back to coil + wire for connection.

a. I used a remote starter at the solenoid to jump.  The car cranks, fires (like when turning the ignition key), then dies when I let go of the trigger. 
b. I tested voltage at the post with the key in the ON position, and there's zero volts.  (I expected 12).  Making a logical leap, I placed a jumper between the pos battery terminal and the "I" post on the solenoid, turned the key to the ON position, and used a remote starter on the "S" terminal.  The car would crank, but not fire.
c. At this point I checked the battery, and it's putting out well over 12V.



ZOINKS!!!   There's been a recurring theme in the suggestions of checking ground and making sure the system is grounded.  Are there some key ways I can measure for this?  Everything I've visually seen so far indicates solidly-connected grounds. 

The lack of voltage at the brown wire (the "I" post) when the key's in the ON position makes me think the problem does lie with the brown wire.  Does that make sense?  If so, I'd have to go back and look at the wire at where I spliced in the resistor wire bypass.  I didn't touch the "brown wire side" of the plug connector, but maybe it's come loose or disconnected (???)

The only other things I can note that are different about the wiring setup are:
* I'm running a single-wire alternator
* I disconnected an aftermarket tach while I was installing the resistor bypass wire.  It was a bolt-on (no original tach in the car).  One of the wires ran to the neg. post on the coil.  I can't understand how removal would cause the problem, but ???

Other suggestions are greatly appreciated.

[Midlife]

I had the same problem with Midlife when I first got it: turn the key to CRANK and the engine would catch, but would die immediately after releasing the key to RUN.  I found I had a bad cable connection to the starter; actually, the starter bolt was mostly stripped.  I had to get a new starter and voila!  everything worked as planned.

Here's what I think is happening: when cranking, the starter solenoid is sending full voltage to both the coil and the starter.  The connection to the starter is pulling too many amps, bringing the voltage down, but still good enough for the engine to catch.  When you release the key, the battery voltage is now low due to amperage being pulled by the coil and its now too low by itself and the internals of the starter solenoid to keep the engine going.  It takes a finite amount of time for the battery to recover (a second to nominal voltage?) and a finite amount of time for the starter solenoid to kick in. 

You can ignore the voltage regulator while having starting issues, as well as the aftermarket tach, although it may add a bit more resistance to the ignition circuitry.  I'd examine the connection at the post on the starter itself and replace the starter solenoid as my next steps.  I'd even consider putting in another starter if those two things don't help.

[Mach1Rider]

Check your bypass wire connections.
You should have same voltage at coils +side and sol I side with key in on position.
Lacking voltage to these points with the key on is what is causing it not to run.
Possiable bad ign switch function or wire connections.
Verify that you are getting voltage from the ign switch with the key in on position at the splice point of your bypass wire.

[66benchcoupe]

The lack of voltage at the brown wire (the "I" post) when the key's in the ON position makes me think the problem does lie with the brown wire.  Does that make sense?  If so, I'd have to go back and look at the wire at where I spliced in the resistor wire bypass.  I didn't touch the "brown wire side" of the plug connector, but maybe it's come loose or disconnected (???)

So that sounds like the brown wire or the ignition switch.  If I still had my 67 manual I'd look at the schematic - but I sold it to Randy. . .

How do the plugs look?  All your spark plug wires are OK?

EDIT: The problem could also be the starter relay.

Robert

[66benchcoupe]

Here's what I think is happening: when cranking, the starter solenoid is sending full voltage to both the coil and the starter.  The connection to the starter is pulling too many amps, bringing the voltage down, but still good enough for the engine to catch.  When you release the key, the battery voltage is now low due to amperage being pulled by the coil and its now too low by itself and the internals of the starter solenoid to keep the engine going. 

That's an interesting theory.  But wouldn't the alternator supply the voltage needed to run the engine?  While the engine is cranking the voltage at the battery should drop to 8 volts or so (I've noticed this from chasing down starter gremlins in the past).  If it drops any lower then maybe a new starter or putting to battery on a charger overnight is in order.

Robert

[Midlife]

That's an interesting theory.  But wouldn't the alternator supply the voltage needed to run the engine?  While the engine is cranking the voltage at the battery should drop to 8 volts or so (I've noticed this from chasing down starter gremlins in the past).  If it drops any lower then maybe a new starter or putting to battery on a charger overnight is in order.

Robert

The alternator only works when the engine is running at rpms above 600 or so.  During cranking, the alternator is out of the circuit.

Battery voltage drop while cranking is expected; it's the nature of the voltage source (battery) that large current loads drops the voltage.  Most drops are down to the 10.5V region; 8V seems a bit low to me.

[cmayna]

That's an interesting theory. Robert

You should hear his theory about how sheep herders stay warm in winter   

[gtscode]

Sorry Bill I have lots of 67 wiring diagrams if you want to borrow them just let me know.

Also I power my Pertronix from just before the pink resistor wire and it works great. I didn't cut anything made a little Y splitter out of wire and crimped it all together.

[DEL65]

Bill, I can volunteer to let you use my 65 manual trans mini starter. Not sure it will work with a 68 auto trans.  OR Sac69's 351W auto trans mini starter.

[Sacbill]

I went back to measuring voltage with the ignition switch in the ON position.  This time I was reading 0 volts at the coil.     That was a spot where I have been measuring 12volts!

I went under the dash and started looking at the wiring, checking for looseness, moving things around, and so forth.  I couldn't see anything amiss.  This makes no effin' sense.  So, I measure again with the key in the ON position:

12V at electric choke? Check.
12V at coil pos terminal? Check.
12V at I post on solenoid? CHECK.

Turn the key.  The car starts right up and runs.   

My guess is that moving the wires around at the back of the ignition switch corrected the problem with power going out to the now-bypassed pink wire.  I don't think it's the splice I made on the bypass wire.  I checked those closely while I was doing them and they seemed very secure.

My question to y'all:  Is it a problem with the ignition switch itself? (NOTE:  It's not the original switch.  I replaced it in 2003)  Or is it a problem with the connectors at the end of the wire that contact the ignition switch? TIA!

[Midlife]

All right...whose the wise guy that put the Smoke Jeannie back in the wires?

To answer your question, there's no way of telling where the faulty connection is.  Your best bet is to get the car running and start jiggling wires.  Where and when you can reliably start and disable your car, you'll find your fault.