D

dahugo

Member
Just finishing up my RV9a project with IO320. Do I really need a fuel pressure sensor? When I turn on the fuel pump I can hear when it pumps fuel. What's the downside of not having one?
 
Flew my -6 for 18 years without fuel pressure indicator. Never had a problem.
Actually I have an audible fuel pressure gauge. As long as the fan up front is making noise, I have fuel pressure.
 
I would say that if you have a carb it's not really necessary,but for fuel injection it would definately be on my "highly recommended" list.
 
It is very handy if you run your tanks low

The fuel pressure will drop before the engine is affected (well on a "O" model anyway) and this gives you a chance to switch tanks before the actual engine operation is interrupted. A restart can ba a problem even when you have some fuel left in the other tank. In cruise configuration I have 4 tanks and on long trips I typically run the tip tanks near dry with my eye on the clock to .8 hrs and the fuel pressure gauge for pressure drop whichever comes first, with my hand on one of the fuel selector valves.

Bob Axsom
 
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Along oil pressure gauge, FP gauge is of high importance to me, and I monitor it as frequntly.

If there is any abnormality in my FP, the guage will warn me which I think it is critical and it will give me as much advance notice about fuel issue to the engine.
 
I have to agree with Walt. I have a carb. I didn't notice that you were "IO".
I would certainly want a pressure gauge with FI.
 
I have an IO, and had my Dynon alarm on low fuel pressure yesterday on a flight from Hoquiem KHQM back to my home base at Arlington.

My fuel pressure usually runs at about 27 psi on the engine driven mechanical, and I have the alarm set at 17 psi. Yesterday, the pressure dropped to 12 psi, but the engine was still running just fine! I immediately turned on the electric fuel pump, which brought pressure back up to 29 psi indicated. After a few minutes, I turned the electric fuel pump off - pressure dropped back to 12 psi. After cycling the electric pump on and off twice, the pressure stayed up at 27 psi with the electric pump off.

I still don't know what caused the problem. There is no fuel leaks evident. My fuel burn was normal before, during, and after the event. I'm very nervous about getting back in the air until I figure this one out.:(

For reference, my fuel pressure transducer is located on a manifold located on the firewall, and gets its pressure from a Tee that is on the engine side of the engine driven mechanical pump.
 
DakotaHawk said:
I have an IO, and had my Dynon alarm on low fuel pressure yesterday on a flight from Hoquiem KHQM back to my home base at Arlington.

My fuel pressure usually runs at about 27 psi on the engine driven mechanical, and I have the alarm set at 17 psi. Yesterday, the pressure dropped to 12 psi, but the engine was still running just fine! I immediately turned on the electric fuel pump, which brought pressure back up to 29 psi indicated. After a few minutes, I turned the electric fuel pump off - pressure dropped back to 12 psi. After cycling the electric pump on and off twice, the pressure stayed up at 27 psi with the electric pump off.

I still don't know what caused the problem. There is no fuel leaks evident. My fuel burn was normal before, during, and after the event. I'm very nervous about getting back in the air until I figure this one out.:(

For reference, my fuel pressure transducer is located on a manifold located on the firewall, and gets its pressure from a Tee that is on the engine side of the engine driven mechanical pump.
Click to expand...

If it always came back up to normal with the electric on, I would just replace the mechanical pump.
 
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