David-aviator
Well Known Member
Recently I got around to reading an article from a friend on rough idle issues. It was published in March 2009 in LPM (Light Plane Maintenance).
My engine idles OK, I read the article just to see what the author had to say about the subject. That led to an issue of relatively high manifold pressure at idle, an indication of a possible induction leak. The author says anything less than 16" is ok although 10-12" is better. I checked mine this morning and it is 14-15" during taxi, right on the edge of maybe a leak. Interesting. The intake pipe clamps need checking next time the cowl is off.
However, later in flight at idle power, manifold pressure was 8-9". Also very interesting some more. Does anyone know what's going on here? Does the FM200 controller have a feature to increases MP on the ground with low air flow through it?
With 8-9" MP in flight at idle, I don't think I have an intake leak.
I'd call Don at AFP but its a week end.
My engine idles OK, I read the article just to see what the author had to say about the subject. That led to an issue of relatively high manifold pressure at idle, an indication of a possible induction leak. The author says anything less than 16" is ok although 10-12" is better. I checked mine this morning and it is 14-15" during taxi, right on the edge of maybe a leak. Interesting. The intake pipe clamps need checking next time the cowl is off.
However, later in flight at idle power, manifold pressure was 8-9". Also very interesting some more. Does anyone know what's going on here? Does the FM200 controller have a feature to increases MP on the ground with low air flow through it?
With 8-9" MP in flight at idle, I don't think I have an intake leak.
I'd call Don at AFP but its a week end.