- Joined
- Feb 19, 2013
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- 73
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I am trying to trouble shoot a problem. During idle after engine is warmed up, rpm suddenly drops 50-100 rpm then comes back up again with a frequency of every 5-10 seconds. Further during shut down, when pulling the mixture out, there is no increase in RPM. I tried to adjust the idle mixture wheel to rich and it did nothing. I turned the wheel several turns. >6 and no increase in RPM. No change in idle characteristic.
I contacted lycoming and they suggested it could be fuel vaporizing in the line. This can be caused by an induction leak or idle mixture out of adjustment or possibly a malfunctioning Sniffle valve.
The engine runs smooth after 1300 rpm and in the air
The engine is an 0-360 A1A with a fuel injection system added onto it.
So one question is, does it make any sense that the idle mixture turned several turns out to rich made no impact at idle. Any thoughts on why the idle mixture adjustment would do nothing? I have heard this should be a very sensitive adjustment. Also, Any ideas on what the problem might be?
Thanks in advance for your thoughts
I contacted lycoming and they suggested it could be fuel vaporizing in the line. This can be caused by an induction leak or idle mixture out of adjustment or possibly a malfunctioning Sniffle valve.
The engine runs smooth after 1300 rpm and in the air
The engine is an 0-360 A1A with a fuel injection system added onto it.
So one question is, does it make any sense that the idle mixture turned several turns out to rich made no impact at idle. Any thoughts on why the idle mixture adjustment would do nothing? I have heard this should be a very sensitive adjustment. Also, Any ideas on what the problem might be?
Thanks in advance for your thoughts
