Diagnosis Quiz for ClassicZcar Readers:

[LeonV]

Car wouldn't restart the next day, cold. Not getting any spark.

How would you diagnose the ignition module, lacking an oscilloscope? What would you start by checking?

Well, if the coil wasn't sending spark to the distributor (correct?), I'd start by checking simple things before messing with the module. In other words, quick volt & ohm check on the coil to ensure the primary and secondary windings are OK and that there is close-to battery voltage present at coil +. Check for battery voltage at module as well.

Then check the triggering mechanism: reluctor, pickup coil, etc. assuming that the ignition system is indeed similar to the electronic ones found in Zs.

[Wade Nelson]

Well, if the coil wasn't sending spark to the distributor I'd start by checking simple things before messing with the module.

In other words, quick volt & ohm check on the coil to ensure the primary and secondary windings are OK and that there is close-to battery voltage present at coil +. Check for battery voltage at module as well. .

You're on the right track.

Probably faster to check the coil functionally. Remove 12V or ground and see if it produces a spark. A test light connected to the coil OR the module should flash as the engine was cranked, indicating the coil was being charged/discharged, points were opening / closing, etc.

In this case there was no 12V to the ignitor module. An ignition relay upstream had worn out, dirty contacts. That's why it worked one final time and then no more.

Hopefully this vehicle was "similar enough" to a 280Z / ZX to provide a useful lesson the next time someone has a crank, no start situation that is NOT rectified by adding faux fuel.

THANKS FOR PLAYING! GAME OVER!