taverroi
Well Known Member
I'm operating and IO-360 M1B in my RV-7A
Ok so heres the deal:
PROBLEM: Fuel pressure after flight drops below 15psi when taxing for a minute or two...EFIS warns me in red flashes..and if left without a boost recovery engine will cut off (sometimes, other times just spit and sputter and hover around 12-15psi) .. boost bring pressure back up to 27-28psi..when boost is then cut back off pressure drops into the red again. pressure can not be recovered under higher engine power only under boost. Keep in mind...all is well while flying without boost..this only happens when I land and am taxing back to the hanger.
Now on initial start up and run up there are no fuel prssure issues. Standard start procedure is...3sec of elec boost, then off...Engine start under mechanical pump...warm up and taxi...run up checks good...elec boost on for take off...1200agl boost off...mechanical pump pressures fine for all of flight (stays between..say...23-26psi.
One mechanic has said its vapor locking after landing because of the reduced airflow in the cowling and that in flight airflow is sufficiently cooling the fuel lines to prevent vapor lock...hmmm
Another has said vapor lock does not happen when the engine is running, but only after shut down and sitting and that the fuel pump in going bad and needed to be replaced.
Ok, so I replaced the pump with a brand new high pressure pump. Operation was flawless..Inial ground test showed 29 psi.. no boost with the new pump..test flight flawless...operating pressure..no boost bwt 23-26 in flight...even landed it this time with no boost pump on..everything perfect..right up until i was on the ground and taxing a minute or so and the the problem returned.
Soooooo. I know that the pump was not going bad..$650 bucks spent for nothing (parts and labor of course)...So what gives?...Has anyone had the same experience? is this normal for fuel injection engines?..Ive been told that the pressure after flight without any boost should remain at the same levels that I see in flight..Can I continue to fly and feel confindent that all is well?
Please help me if you can...what can I do?..suggestions?.. Please somebody...
Tango
Ok so heres the deal:
PROBLEM: Fuel pressure after flight drops below 15psi when taxing for a minute or two...EFIS warns me in red flashes..and if left without a boost recovery engine will cut off (sometimes, other times just spit and sputter and hover around 12-15psi) .. boost bring pressure back up to 27-28psi..when boost is then cut back off pressure drops into the red again. pressure can not be recovered under higher engine power only under boost. Keep in mind...all is well while flying without boost..this only happens when I land and am taxing back to the hanger.
Now on initial start up and run up there are no fuel prssure issues. Standard start procedure is...3sec of elec boost, then off...Engine start under mechanical pump...warm up and taxi...run up checks good...elec boost on for take off...1200agl boost off...mechanical pump pressures fine for all of flight (stays between..say...23-26psi.
One mechanic has said its vapor locking after landing because of the reduced airflow in the cowling and that in flight airflow is sufficiently cooling the fuel lines to prevent vapor lock...hmmm
Another has said vapor lock does not happen when the engine is running, but only after shut down and sitting and that the fuel pump in going bad and needed to be replaced.
Ok, so I replaced the pump with a brand new high pressure pump. Operation was flawless..Inial ground test showed 29 psi.. no boost with the new pump..test flight flawless...operating pressure..no boost bwt 23-26 in flight...even landed it this time with no boost pump on..everything perfect..right up until i was on the ground and taxing a minute or so and the the problem returned.
Soooooo. I know that the pump was not going bad..$650 bucks spent for nothing (parts and labor of course)...So what gives?...Has anyone had the same experience? is this normal for fuel injection engines?..Ive been told that the pressure after flight without any boost should remain at the same levels that I see in flight..Can I continue to fly and feel confindent that all is well?
Please help me if you can...what can I do?..suggestions?.. Please somebody...
Tango