Jeff's test seems to show that the TCM fuel system works well (if setup
correctly) and is even tolerant of potentially incorrectly applied high
boost, (at least within the range of his test conditions).  Jeff, can you
pls share your test conditions i.e. density altitude, power settings, etc
and re-confirm your normal fuel flow set points.

Rick,

 

Excellent points! I tested the "high boost" position yesterday on my return flight from Denver. I was at 5000' MSL arriving at KSUS when I took a few minutes to check this out.

 

Parameters:

5000' MSL

ISA+20 degrees

MAP 32"

Rpm 2550

Fuel Flow 29 GPH (mixture full rich)

 

Turned on boost pump and fuel flow increased 5 GPH.

 

Same parameters from a Lean of Peak Operation at 17.2 GPH (yes, Bob, I know what Lean of Peak is-- I took the course at Ada from the best guys in the business) going to "high boost" increased fuel flow by 4 GPH.

 

As I stated earlier, if your system is set up correctly this should be a non event BUT just in case it is not set up properly and your engine sputters on takeoff then check fuel flow. 50 GPH at WOT is too much for a TSIO 550. Reduce fuel flow with mixture knob. Pretty simple.

 

Jeff Edwards, CFI

(simple flight instruction provided)