Pilotdaddy
Well-Known Member
- Joined
- Apr 15, 2020
- Messages
- 89
- Reaction score
- 24
Hi everyone,
I wanted to see if the below is entirely normal or should be a cause of concern for me going forward. I'm starting to think that my fuel pump and/or gauge is going bad but the conflicting scenarios make it hard for me to decide which (maybe both) is/are the culprit.
1st observed abnormality: during run-up to 2000 rpm, and with the electric fuel pump off, the fuel pressure gauge was observed to be very low.... not in the red, but just a speck above the red line. When the electric fuel pump was turned on, pressure builds to about the middle of the fuel pressure gauge. My instructor and I think... ok, the gauge must be working and the electric fuel pump must be working... but the engine driven one is suspect. We do another run up with the electric fuel pump off at 2200 rpm time time, and after about 5 seconds, the low pressure reading came back to normal... so we went ahead and flew without any trouble.
This suggests, to me, that the engine driven fuel pump may be on its last legs... or there must be some sort of fuel blockage of sorts.
2nd observed abnormality: run-up was good and was lined up to take off with the fuel pump on. During the roll, I check RPMs, oil pressure and temps, and I notice that my fuel pressure is again very low. Not in the red, but definitely close to it.... I'd say less than 1 PSI. This is the first time I've noticed this but I continue on because it was technically still in the green. I climb to my cruise altitude and, before reducing throttle, I turn the electric fuel pump off.... this actually caused the low fuel pressure reading to suddenly read in the normal range again! At this point, I'm extremely confused.
This suggests, to me, that there must be some sort of blockage (fuel vents maybe?) as the gauge seemed to definitely be working.
Are these fluctuations normal or is it something to worry about?
I wanted to see if the below is entirely normal or should be a cause of concern for me going forward. I'm starting to think that my fuel pump and/or gauge is going bad but the conflicting scenarios make it hard for me to decide which (maybe both) is/are the culprit.
1st observed abnormality: during run-up to 2000 rpm, and with the electric fuel pump off, the fuel pressure gauge was observed to be very low.... not in the red, but just a speck above the red line. When the electric fuel pump was turned on, pressure builds to about the middle of the fuel pressure gauge. My instructor and I think... ok, the gauge must be working and the electric fuel pump must be working... but the engine driven one is suspect. We do another run up with the electric fuel pump off at 2200 rpm time time, and after about 5 seconds, the low pressure reading came back to normal... so we went ahead and flew without any trouble.
This suggests, to me, that the engine driven fuel pump may be on its last legs... or there must be some sort of fuel blockage of sorts.
2nd observed abnormality: run-up was good and was lined up to take off with the fuel pump on. During the roll, I check RPMs, oil pressure and temps, and I notice that my fuel pressure is again very low. Not in the red, but definitely close to it.... I'd say less than 1 PSI. This is the first time I've noticed this but I continue on because it was technically still in the green. I climb to my cruise altitude and, before reducing throttle, I turn the electric fuel pump off.... this actually caused the low fuel pressure reading to suddenly read in the normal range again! At this point, I'm extremely confused.
This suggests, to me, that there must be some sort of blockage (fuel vents maybe?) as the gauge seemed to definitely be working.
Are these fluctuations normal or is it something to worry about?
