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Fuel pump pressure
Posted: Fri Jul 31, 2009 12:29 am
by Kurt Aichele
What, if anything, regulates the fuel pump pressure on the '48 ragwing? We just replaced the fuel pump with a rebuilt from Spruce. The fuel pressure is now above the green arc.
Re: Fuel pump pressure
Posted: Sun Aug 02, 2009 7:15 pm
by DWood
I can't think of any control for the fuel pressure except for the pump itself. The check valve only controls the direction of flow. The next time I start mine, I will verify the pressure and advise on what I am getting. I replaced my pump about 2 years ago.
Dan
Re: Fuel pump pressure
Posted: Tue Aug 04, 2009 2:06 am
by n3833v
If I recall, my pressure runs between 4 & 5.
John
Re: Fuel pump pressure
Posted: Wed Aug 05, 2009 5:15 am
by GAHorn
Kurt Aichele wrote:What, if anything, regulates the fuel pump pressure on the '48 ragwing? We just replaced the fuel pump with a rebuilt from Spruce. The fuel pressure is now above the green arc.
Have you confirmed the calibration of your guage?
Re: Fuel pump pressure
Posted: Thu Aug 06, 2009 3:35 am
by Kurt Aichele
Have not checked calibration yet. Also noticed there is a lot of needle flutter at engine idle, which I did not have with the old fuel pump.
Re: Fuel pump pressure
Posted: Thu Aug 06, 2009 12:34 pm
by DWood
I flew mine last night and the pressure is running around 5 psi. Of course the gauge was calibrated at the factory some 60 plus years ago or replaced and not entered in the logs. The interesting thing is that the green arc on the guage is 0 to 2 psi and the red line is 5.5 or so. I can't believe 0 would be in the green arc. As far as I remember the pressure has always been around 5 PSI and the only reason I replaced the pump is that I couldn't tighten the top half anymore to stop the leaks.
Dan
Re: Fuel pump pressure
Posted: Thu Aug 06, 2009 8:45 pm
by Kurt Aichele
Same thing with ours. Could not stop the leak, so we replaced it.
Re: Fuel pump pressure
Posted: Sun Aug 09, 2009 1:01 am
by mrpibb
I run about 4 psi on mine, and the needle "flutters" at lower rpm ( mechanical diaphram pump), the perks of a 48, plus we get a extra gauge in our dashboard
Mine was weeping a few years back, fixed by installing a new gasket kit from aero accessories, i dont know if they still have the kits, p/n is listed in the tcm SB m81-8r1. BTW my pump p/n specs out to 3.5 to 4.5 psi.
Re: Fuel pump pressure
Posted: Wed Sep 09, 2009 1:32 am
by Kurt Aichele
Finally got back up in the air yesterday. Checked the fuel pressure gauge. Flutters between 3 and 6 psi at idle and between 4 and 6 psi at 2450 rpm with the new fuel pump. Seemed like the old fuel pump held a steady pressure at cruise power and fluttered at idle. Is this normal? Also, could this damage the gauge in the long run?