macrafic
Well Known Member
I have been flying the RV-7A, with IO-360, 2 pMags, and G3X system since 2017, with no issues.
Recently, the gph reading on the G3X Fuel Calculator tab on the Engine page became inconsistently high at times. When I would expect 7.0 gph, I may get that for some of the flight; then the gph would jump to approximately double that. No amount of throttle/mixture adjustment would return the reading to an accurate one. However, later in the flight, it may do it on its own (inconsistent, as I said).
That might be alarming (When it happened the first time, I really envisioned fuel draining out the bottom of the plane!), until I realized that the G3X reading of the flop tubes in the tanks (at the top of the Fuel Calculator tab), which I had to calibrate way back when, were reading accurately all the time. I verified this the last couple of flights by comparing the fuel I added at the end of the flight with the flop tube reading. So, it is only the bottom fuel readings on the Fuel Calculator page that are inconsistent.
I can only think of 2 things that might be the source. One would be the fuel sensor that is installed in the manifold on my firewall. The other would be the red cube. I am leaning (and hoping) that the fuel sensor is the issue. Before I plunk down any money, however, I wanted to pass it be the expertise on this site to see if they have experience with this and can validate my troubleshooting, or tell me other possible sources that I may be missing.
Recently, the gph reading on the G3X Fuel Calculator tab on the Engine page became inconsistently high at times. When I would expect 7.0 gph, I may get that for some of the flight; then the gph would jump to approximately double that. No amount of throttle/mixture adjustment would return the reading to an accurate one. However, later in the flight, it may do it on its own (inconsistent, as I said).
That might be alarming (When it happened the first time, I really envisioned fuel draining out the bottom of the plane!), until I realized that the G3X reading of the flop tubes in the tanks (at the top of the Fuel Calculator tab), which I had to calibrate way back when, were reading accurately all the time. I verified this the last couple of flights by comparing the fuel I added at the end of the flight with the flop tube reading. So, it is only the bottom fuel readings on the Fuel Calculator page that are inconsistent.
I can only think of 2 things that might be the source. One would be the fuel sensor that is installed in the manifold on my firewall. The other would be the red cube. I am leaning (and hoping) that the fuel sensor is the issue. Before I plunk down any money, however, I wanted to pass it be the expertise on this site to see if they have experience with this and can validate my troubleshooting, or tell me other possible sources that I may be missing.