EE Question -- Some Kind of Circuit Interference with AC Clutch Spark Table Switching
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I recently made a software mod to fix my 1st gen MSPNP AC idle once and for all:
https://www.miataturbo.net/megasquir...de-hack-73751/
While I was working on implementing this, I discovered that the MSPNP was not doing spark table switching as expected. When I first installed the MSPNP, I implemented spark table switching and verified operation. At a later date, I also implemented the purge valve solenoid mod. These two circuits looked like this (1J to AC Clutch, 2X to Purge Valve Solenoid):
![](https://www.miataturbo.net/attachments/megasquirt-18/81895d1373386531-ee-question-some-kind-circuit-interference-ac-clutch-spark-table-switching-question.jpg)
Long story short, when I removed the purge valve solenoid circuit from 1J, spark table switching began working again. This is OK because with the code hack I don't need the purge valve anymore, but it bothers me that I don't know why there was interference. It looks like it should have worked OK. ??
https://www.miataturbo.net/megasquir...de-hack-73751/
While I was working on implementing this, I discovered that the MSPNP was not doing spark table switching as expected. When I first installed the MSPNP, I implemented spark table switching and verified operation. At a later date, I also implemented the purge valve solenoid mod. These two circuits looked like this (1J to AC Clutch, 2X to Purge Valve Solenoid):
![](https://www.miataturbo.net/attachments/megasquirt-18/81895d1373386531-ee-question-some-kind-circuit-interference-ac-clutch-spark-table-switching-question.jpg)
Long story short, when I removed the purge valve solenoid circuit from 1J, spark table switching began working again. This is OK because with the code hack I don't need the purge valve anymore, but it bothers me that I don't know why there was interference. It looks like it should have worked OK. ??
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