Toobuilder
Well Known Member
Unless you're mounting a gascolator after the fuel pump where is no pressure, it's flow...
But you do mount the gascolator after the boost pump...
Unless you're mounting a gascolator after the fuel pump where is no pressure, it's flow...
But you do mount the gascolator after the boost pump...
But you do mount the gascolator after the boost pump...
No. You mount the gasculator, on the firewall, from the fuel valve / tank. There's is no pressure. From the output of the gascolator it feeds the backup pump, from there to the mechanical pump. At this point you can collect any contaminants before it enters the pumps.
Where you mount it makes no difference. Pressure and flow are two different measurements, like amps and volts. Just because you're pulling doesn't mean there is no pressure. Just like you in the wind tunnel, the gascolator can't tell the difference between a fuel pump before it or after it.
So, if you disconnected the fuel line from the gacolator and let the fuel pour out, you're saying there's high pressure?? That is less fuel then the pump is FLOWING though it.
Since this thread got a bit side tracked.. The question is???? Did you get your problem solved??
No. You mount the gasculator, on the firewall, from the fuel valve / tank. There's is no pressure. From the output of the gascolator it feeds the backup pump, from there to the mechanical pump. At this point you can collect any contaminants before it enters the pumps.
Where you mount it makes no difference. Pressure and flow are two different measurements, like amps and volts. Just because you're pulling doesn't mean there is no pressure. Just like you in the wind tunnel, the gascolator can't tell the difference between a fuel pump before it or after it.
You should ground the aircraft and find someone qualified to help you sort this out before you become a statistic
This is still the best advice you have received to date. Dust off your cheque book and get some professional assistance.
Also, servo is precision model RSA-5AD1/2576535-A Serial #70242209
I don't have a problem paying someone, but at this point what are they going to do? Tear the plane apart trying to diagnose a problem with no current symptoms? I just had a conversation with Don at Airflow Performance about the engine quitting, the water in the airbox and the cleaning and at this point I feel pretty comfortable with it. On the ground the engine runs great from idle to full throttle hot and cold.
I have not been able to replicate the low fuel pressure with the mechanical pump, but the boost pump restored normal pressure so that's not an emergency issue. No problems with the ignition system and no symptoms of issues with the fuel controller. Tearing apart the plane looking for a problem can potentially create a problem. I know this fact is largely lost on the GA community, but most failures occur soon after maintenance or overhauls. There is a very reasonable explanation for the engine quitting, albeit an impossible one to confirm. I very much appreciate everyone's input and concern, but at this point I feel like the potential downside of messing with a plane that is running great outweighs the small possibility that something else is wrong.
My Precision servo install instructions say to put a cleanable 30 micron filter either immediately before or after the mechanical fuel pump. Does your Usher gascolator have a screen and if so, what size is the mesh?
The Precision servo also has a very fine filter in the inlet but it has very small capacity. Considered to be a "last resort" filter. Have you checked this filter?
I don't see why the gascolator has to be on the firewall where it will pick up heat.
Bevan