Larry J Roth
Cadet
- Joined
- Jul 30, 2015
- Messages
- 6
Good day to you all. I have a GM Mercruiser 5.0, 1999, Carbureted, Alpha One Gen II, Thunderbolt IV apparently. There is no knock module or sensor. The timing is set at 500 RPM to 10 degrees BTDC. Upon opening of the throttle, it momentarily drops to TDC and then back to 10. Next it will NOT advance at all until 3000 RPM. Then it begins to advance what seems to be linearly.
Voltage into module is over 13. Grounds are good. Sensor has been inspected and cleaned. Module says "5.0 Alpha" Nothing has made a difference.
I have been working Mercruisers for a while but have never seen this before. I am thinking that the module is bad but I have not changed the sensor. In my past experience the sensors work or are fully failed resulting in no spark.
I am truly at a loss other than the module is failing. I hope someone can help.
Thank you in advance.
Voltage into module is over 13. Grounds are good. Sensor has been inspected and cleaned. Module says "5.0 Alpha" Nothing has made a difference.
I have been working Mercruisers for a while but have never seen this before. I am thinking that the module is bad but I have not changed the sensor. In my past experience the sensors work or are fully failed resulting in no spark.
I am truly at a loss other than the module is failing. I hope someone can help.
Thank you in advance.
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