TEST 6: Checking For Carbon Tracks
If your 3.2L Isuzu Amigo, Isuzu Rodeo, Isuzu Trooper or Honda Passport is experiencing a misfire condition and all of the ignition coils are good, then the most likely causes are:
- The spark plug boots and spark plugs have developed carbon tracks.
- The spark plugs and spark plug boots are swimming in engine oil.
The two conditions listed above are a very common occurrence in this type of Coil-On-Plug ignition coil ignition system.
If the spark plug boots spark plugs are swimming in engine oil, it's usually due to the valve cover gasket leaking oil into the spark plug tubes. This oil will cause the ignition system to misfire and/or cause carbon tracks to form as the spark cooks the oil.
In the image above, you can see what a carbon track looks like on the spark plug boot and on the spark plug. The next step is to remove the spark plugs and spark plug boots to visually inspect them for carbon tracks and/or to see if they are all oil-soaked.
If the spark plugs are oil-soaked and/or with carbon tracks, you'll need to replace them all along with the spark plug boots. Failure to replace one without the other will only make the carbon track return and/or continue to misfire still.
Now, if no carbon tracks are visible on any of the spark plugs, or spark plug boots, then the ignition system is not the cause of your misfire condition. I would check engine compression and the fuel injectors among several things.
The following test tutorials may be of help:
- How To Test Engine Compression (3.2L Isuzu Amigo, Rodeo, Trooper).
- How To Test The Fuel Injectors (3.2L Isuzu Amigo, Rodeo, Trooper).
Where To Buy The Ignition Coils And Save
The following links will help you comparison shop for the ignition coils:
1996-1997 3.2L Isuzu Rodeo, Trooper, and Honda Passport:
1998-1999 3.2L Isuzu Amigo, Rodeo, Trooper, and Honda Passport:
More 3.2L Isuzu Diagnostic Tutorials
You can find a complete list of 3.2L Isuzu tutorials in this index: Isuzu 3.2L Index Of Articles.
Here's a small sample of the tutorials you'll find in the index:
- How To Test The Isuzu 3.2L Throttle Position Sensor.
- How To Test The Isuzu Manifold Absolute Pressure (MAP) Sensor.
- Ignition Control Module Test (1992-1995 3.2L Isuzu Rodeo and Trooper).
- How To Test The GM MAF Sensor (3.1L, 3.4L, 4.3L, 5.0L and 5.7L).
- For GM MAF sensor equipped 3.2L Isuzu Rodeo.
If this info really saved the day, buy me a beer!