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Faulty ignitor or coil...

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Ronanmd Avatar
Ronanmd Jason Lord
Calgary, Alberta, Canada   CAN
My car continues to test me. A bit of history. The original electronic ignition went up in smoke a few weeks back when I replaced the coil with one that did not have the same resistance as the original. The PO informed me that he had installed the electronic ignition b/c the distributor shaft was worn, and he had struggled to get the gap set properly on the points. Temporarily, I removed the electronic ignition, and installed new points, rotor and condenser, as well as the correct coil. Also replaced plugs, distributor cap and wires. I also replaced my fuel pump with a new one. All was running pretty well.

I then installed a new pertronix distributor/electronic ignition and petronix coil. The car had been running fantastic for about a week or so. Then today, while driving home, it just died. After I pulled over to the curb, it wouldn't start again. It turned over, but wouldn't fire. Occasionally it would stumble for a second or two, and then die again. I figured it was either fuel or spark. I confirmed that the pump was delivering fuel by disconnecting a hose and turning it over. I then pulled the distributor and coil and replaced with the original ones (which I had kept in the trunk with some tools...just in case winking smiley) That solved the problem. Car fired right up and drove fine all the way home.

So either my ignitor is pooched, or the coil failed. I plan to contact TRF to replace one or both under warranty.

Quick question - Is the Pertronix coil the same as the standard Lucas one? Can I simply replace the Lucas one that is currently in my car with the Pertronix one that I removed and then run the car to see if it is the problem? Is the resistance the same between the two?

Thanks guys. Always an adventure!

Jason

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TR3driver Randall Y
Confusion, Los Angeles, USA   USA
Pertronix offers coils in several different primary resistances, so the answer is "it depends". If you got the 3 ohm version, then it should be a drop-in for the stock coil on your early TR6.

But if you got the 1.5 ohm version (which is more common), then you just had the same problem again (minus the flames).

PS, same thing is true of Lucas and almost all other coil makers. You can't tell the resistance from the brand name.



Randall
56 TR3 TS13571L daily driver
71 Stag LE1473L awaiting engine rebuild
7? Stag awaiting gearbox rebuild



Edited 1 time(s). Last edit at 2017-08-05 11:50 PM by TR3driver.

Ronanmd Avatar
Ronanmd Jason Lord
Calgary, Alberta, Canada   CAN
They were ordered as a pair through TRF. I would imagine they would have matched them appropriately and sent the correct coil. I may just put the dizzy with the electronic ignition back in and then try it with my original (non-pertronix) coil. I know that one is 3ohm. At least then i could eliminate one potential source of the issue.

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TR3driver Randall Y
Confusion, Los Angeles, USA   USA
What part number is for the "pair" ? In general, they don't do things like that, especially in this case since which coil you need depends on which year TR6 you have and (for the later ones) whether the ballast resistance has been bypassed or not.



Randall
56 TR3 TS13571L daily driver
71 Stag LE1473L awaiting engine rebuild
7? Stag awaiting gearbox rebuild

Ronanmd Avatar
Ronanmd Jason Lord
Calgary, Alberta, Canada   CAN
Hi Randall - Technically not sold as 'pair'. My car is a 1962 TR4 (not TR6). Both coil were from TR4 - part number PTR201 (listed as early coil the dizzy was part number LU40795/PTXP (new 25D4 with pertronix ignition - positive earth).

Jason

TR3driver Randall Y
Confusion, Los Angeles, USA   USA
Sorry Jason, I get the threads mixed up.

PTR201 should be the right coil. Should work fine with either points or Pertronix.



Randall
56 TR3 TS13571L daily driver
71 Stag LE1473L awaiting engine rebuild
7? Stag awaiting gearbox rebuild

Ronanmd Avatar
Ronanmd Jason Lord
Calgary, Alberta, Canada   CAN
Thanks - Yep, i had a look at the Pertronix coil today. It actually has a sticker that says 3 ohm right on it. I will try replacing it with another 3ohm coil later today.

Jason

In reply to # 1476161 by TR3driver Sorry Jason, I get the threads mixed up.

PTR201 should be the right coil. Should work fine with either points or Pertronix.

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Ronanmd Avatar
Ronanmd Jason Lord
Calgary, Alberta, Canada   CAN
So, I finally had a chance to do some investigating today. Since I have both the original dizzy with points and the original coil, as well as the new dizzy with electronic ignition and flamethrower, I decided to try a few combinations to see if I could isolate the issue. Here is what I found:

1. Original dizzy with points and coil - started fine and ran smooth - no issues
2. Original dizzy with points and flamethrower coil - car started and ran fine but at about 1100 RPM and a regular and repeating stumble or hesitation.
3. New dizzy with electronic ignition and original coil - started fine and ran smooth

So, based on this, I figured the problem was probably related to the coil. Maybe the stumbling I saw was indicative of a bigger issue that revealed itself under load when the coil heated up.

However, I then decided to test the voltage regulator. At idle, the voltage at the battery seems to be constant at about 12.7 volts (with occasional weird spikes up to 15 or 17 volts temporarily). However, when I held the car under acceleration at about 2000 RPM, the voltage seems to bounce all over the place (see video). I would imagine that this is abnormal? If so, could the voltage spikes have caused the electronic ignition to cut out? Maybe this together with a wonky coil?

[url=]Voltage Regulator[/url]

For now, I will put the dizzy with the points back in. I am hoping this will be less sensitive to any voltage swings/spikes that may be taking place.

Thoughts? Advice?

Thanks again for all the help...gotta love the prince of darkness!

Jason



Edited 1 time(s). Last edit at 2017-08-07 02:23 PM by Ronanmd.

JonD Avatar
JonD Jon Distefano
Syracuse, New York, USA   USA
Goin though the same issues with my 7. I will have to take a look at the voltage when my new coil comes in. Does anyone have any suggestions as to how I can protect the new coil while checking the voltage regulator? Would rather not have to buy a third coil because I I killed the second testing the VR.

Thanks!

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TR3driver Randall Y
Confusion, Los Angeles, USA   USA
The coil itself should be pretty much immune to any spikes caused by a failing voltage regulator. Note that on Jon's car, we're talking about the regulator that is inside the alternator, not the one on the back of the speedometer.

Jason, I suggest cleaning and readjusting the generator control box. My experience has been that it's required every few years, even though the book doesn't mention it. Make sure to set the mechanical point gap first, as it affects the voltage adjustment and is important to proper operation. I have no idea why the book lists mechanical adjustment second, as it has to be done first.

But your stumbling at 1100 rpm seems to say the new coil has a problem. Even if there is some other issue being uncovered, you shouldn't be getting a weaker spark than with the original coil.

FWIW, I couldn't see the video. First I got a screen demanding that I create an account, then it wants me to download the "app". I'm kind of picky about what software I install, so I passed.

There is a small rpm range where the voltage can bounce around some, usually you'll see the ammeter bouncing as well. But the range should be limited, no more than 15 volts at the top and around 13 at the bottom. And it should only happen when the available generator output just barely exceeds what it takes to run the car and recharge the battery. What happens is that the points in the TR4 control box close and call for full charge from the generator, until the current plus voltage go high enough to cause them to open. Then it shuts down for a short time, until the output falls off and the points close again. At higher rpm, that happens fairly quickly, but it can be slow enough to see at lower rpm.

I've never noticed that with the solid state Lucas regulator (like the TR7 uses), but I don't have a lot of experience with it either. But logic says it should switch much quicker, plus it doesn't monitor current at all, so I don't think you should see the equivalent effect.



Randall
56 TR3 TS13571L daily driver
71 Stag LE1473L awaiting engine rebuild
7? Stag awaiting gearbox rebuild

Ronanmd Avatar
Ronanmd Jason Lord
Calgary, Alberta, Canada   CAN
Hi Randall - Thanks. The TR4 voltage regulator is located on the firewall. I had tried to upload the video to my dropbox account. I have reloaded it onto youtube, so there should be no need for a password now. See above. I will see if the fluctuations also occur with the RPM held a bit higher.

Jason

TriumphantMan Avatar
TriumphantMan Raymond C
Southeast, Southeast, USA   USA
I have a '63 TR4 with pertronix setup. We experienced a similar problem where the igniter was failing. After several replacements Pertronix suggested that we check the ground. Even though the ground looked ok, I added a ground from the unit and cleaned the battery and engine grounds thoroughly. No issues now, fingers crossed.



Edited 1 time(s). Last edit at 2017-08-11 08:09 AM by TriumphantMan.

JonD Avatar
JonD Jon Distefano
Syracuse, New York, USA   USA
I have the pertronix in my TR7 as well. I went as far as adding a grounding strap from my distibutor to a chassis ground point to alleviate any resistance concerns.

Pertronix is sending me a complete new kit. Will keep you guys posted on progress.

Thanks for the advice!

Ronanmd Avatar
Ronanmd Jason Lord
Calgary, Alberta, Canada   CAN
Hey Jon - do you have pics of that ground set up from the dizzy to chassis?

Thanks,

Jason

JonD Avatar
JonD Jon Distefano
Syracuse, New York, USA   USA
I will grab them tonight for you.

Jon

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