Autonerdz forums

The customer reports that the engine will start but does not idle properly. They are experiencing severe loss of power, and the vehicle runs poorly at all operating speeds. Further diagnostics are needed to identify the underlying issues affecting performance.

The first test conducted was an engine compression test, which revealed that both cylinders are operating normally, indicating that compression is not the issue.

The second test performed was a secondary ignition voltage test. The results indicated that combustion is not occurring in the front cylinder, suggesting a problem with ignition or fuel delivery in that area. Further investigation will be required to pinpoint the exact cause of the lack of combustion.

Upon re-examining the ignition waveforms, I believe the problem lies within the ignition system. I initially swapped the ignition coils, but that didn’t yield any change. However, when I swapped the spark plugs, the issue shifted to the other cylinder. Interestingly, the spark plug appears normal and tests fine with an ohm meter.  Additionally, when connected to the spark plug cap, it produces a strong blue spark. The last attached file is of the unit with both spark plugs replaced. It is running perfectly.

HarleyMike wrote on Mar 25^th, 2025 at 4:26am:


O.K, I have been watching Group Therapy  ( great job, everybody) the topics were interesting.

I will check the Drop Site for the files. They must be to big to post.