A few questions have come up regarding fuel pressure while flight testing Ralph Love's Legacy, N122PT.  It has an IO-550 with MT prop.  We've had indications of high fuel pressure when the throttle is retarded (38-40 psi) in the pattern which is accompanied by engine roughness.  All gets better when the mixture is leaned.  Testing has been done in Redmond - so patterns about 4-5000 ft.  So is this "normal" and just explained by the overly rich state due to altitude and leaning is the solution or is something else going on?  Where should the fuel pressure be measured from?  The unmetered side of the fuel metering unit or the metered side?  and why.    And lastly, where have you mounted the fuel pressure transducer?  EI suggests the firewall, but that leads to a long fuel line and ? does that make any difference in the readings, dampening etc.  Can you mount it closer or are the vibrations going to cause failure of the fitting and fuel leaking over hot cylinders?

Any thoughts or comments will be appreciated.

Thanks

Dan Ballin
LEG2 #286