Triumph Repair: 1980 Spitfire ignition problem, external resistor, secondary windings

Question
Thanks for the info Jim. I was getting +12 volts at both the positive terminal on coil and at the high tension lead. I tried the procedure you described with no arc. Can the luminition resistor or the distributor be the culprit? Thanks again, David -------------------------
Followup To
Question -
I do have a working knowledge of the ignition system.
+my car just died, and it appears that there is no fire coming from the coil. I replaced the coil with no sucsses.
the coil is getting voltage from the start solenoid.
The output from the coil is +12volts. I just don't understand this. what else can be causing this? There is a suppressor coming from the positive terminal on the coil.and the negitive terminal connects to the external resistor. Could either of these be the problem? I welcome any insite to my problem. Thanks
Answer -
David,

You don't mention if you're running the original ignition system.

Where are you measuring 12V?  At the + terminal on the coil?  Or at the high tension lead?

If you don't already know, a traditional ignition system works by putting 12V to the + terminal on the coil and using the distributor system to apply ground to the - terminal.  When the distributor grounds the coil it stores energy in the primary coil.  When the distributor breaks the ground connection that energy is released via the secondary windings in the coil to the high tension lead leading to the distributor cap.

If you still have the original Lucas ignition system a simple test is to pull the high tension lead from the distributor, arrange it so it can arc to ground safely, turn on the ignition and pull the lead from the external resistor.  If the Lucas unit is working correctly you'll see a spark.  If not, either the Lucas unit isn't being properly supplied with power (not impossible) or the unit has failed after 26 years.


Cheers,

Jim

Answer
David,

It is possible that the resistor has failed.  A simple check with a voltmeter will verify whether you're seeing continuity though the resistor.

Otherwise it's likely the electronic ignition module has failed.  There are aftermarket replacements like the Pertronix that are much more reasonable (and available) than the original Lucas unit.


Cheers,

Jim