Vehicle applicability: This diagnostic supplement covers multiple Ford vehicles and engines. Follow the application named in the source below. Some references apply to vehicles other than Mustang.
JC4 CHECK FOR THE IGNITION PATTERN
• Connect an engine analyzer to diagnose concerns in the secondary side of the ignition system.
• Observe the pattern on a scope while cranking the engine.
Is the pattern flat, which indicates no ignition spark on all cylinders?
Yes | No |
|---|---|
GO to Pinpoint Test JE . | GO to JC5 . |
JC5 CHECK FOR A NORMAL IGNITION PATTERN
Note: Spark plugs may be fired more than once per combustion event. Multi-strike operating mode is RPM dependent.
• Ignition ON, engine running. If no start, crank the engine.
Are the patterns even and is the average value of spark plug firing voltage between 9 kV and 15 kV (higher during engine crank/no start)?
Yes | No |
|---|---|
GO to Pinpoint Test Z . | GO to JC6 . |
JC6 CHECK FOR MISSING SPARK PATTERNS
• Observe for missing spark pattern.
2016 Mustang workshop publication supplied to Mustang Atlas. Original technical text and illustrations; HTML formatting by Mustang Atlas. Source page numbering is retained for traceability. Follow the configuration, revision, warnings, and cross-references in the material. About this edition.