In this video I will cover secondary ignition misfire diagnosis using a lab scope. The following waveforms will be shown:

  • A no fuel misfire
  • An open plug or wire
  • A shorted plug or wire
  • A coil output test


Engine Performance Diagnostics chapter 1 pages 13-15


(Chapter 1) Misfire ID, Compression Tests, Vacuum Leaks, Fuel Trim, Head Gasket, Restricted Exhaust, Low Power, DMM

Related videos:

How to find a misfire with no trouble codes (uScope):


Ignition testing with a scope (Secondary Waveforms) - open plug wire:


What does an open plug wire look like on a lab scope (uScope):


Misfire Case Study (1999 Honda Accord):


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For more information on this topic, I have written a “field manual” called Engine Performance Diagnostics which is available as an eBook or paper book.

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