It was a shot FPR!

And I had the opportunity of witnessing the way in which a truly failed FPR vents fuel thru' the vent hose!

Truly obvious and consistent amount - can't miss it.

FAILING FPRs may not exhibit this symptom but a FAILED one definitely will.

The only similarity I noticed about both FAILING/FAILED FPRs is that when disconnecting the fuel return line to the fuel tank, VERY LITTLE fuel is lost frm the line.This should be done immediately after shutting off the engine.

However, disconnecting the same line from a good FPR after shutting off the engine will result in a good flow of fuel lost from the same line!

Good way to check i believe.

I have posted detailed info on my experiences with tese FPRs in another thread for the benefit of others.

Thanks and cheers to all.