Bobby,

 

My Mallory adjustable fuel pressure regulator has the same problem of a vacuum leak through the adjustment screw threads.  Placing a gasket between the jam nut and the regulator body in addition to a gasket between the jam nut and an acorn type nut installed after adjusting the pressure eliminated the leak.  This regulator is also being used at the low end of its rated range and it is unable to maintain a constant fuel pressure better than +/- 3 psi.  This is after other modifications to it since as received, it could not maintain a constant pressure within +/-10 psi.  The archives have more information on this adventure.

 

Steve Boese

 

 

 

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bobby J. Hughes
Sent: Wednesday, May 13, 2009 6:49 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Fuel Pressure Regulator \ Vacuum Leak

 

Al,

 

I will contact Aeromotive tech support today and see if it's possibly a leaking diaphragm that can be fixed. I also suspect raising my fuel pressure from 36 to 40 psi may improve things. I discovered the minimum design operating pressure for this regulator is 40 psi. If the leak is around the adjustment screw then screwing it in further may help. May not.

 

One step forward and two steps back.

 

Bobby's