ArVeeNiner
Well Known Member
I calibrated my capacitance fuel gauges before my first flight a few weeks ago. I also set up my fuel computer at the last fill up. Today, I wanted to see if can hang my hat on either one of these readings and it turns out that I can't.
I disconnected at the carb and ran each tank dry in a calibrated bucket to verify the readings. Here is what I found:
****
Fill up: 13.3 hours
Time at check: 19.0
Elapsed Time: 5.7 hours
Fuel computer reads: 2.0 gallons remaining
Left tank reads: 4.0 gallons
Actual left tank: 3.07 gallons
After 1 gallon drained, fuel quantity dropped from 4.0 to 1.8 gallons.
After 2 gallons drained, fuel quantity stayed at 1.8 gallons.
After 3 gallons drained, fuel quantity dropped to 0.0 gallons.
After an additional 16 ounces drained, fuel quantity stayed at 0.0 gallons.
Right tank reads: 4.0 gallons
Actual right tank: 2.27 gallons
After 1 gallon drained, fuel quantity dropped from 4.0 to 1.8 gallons.
After 2 gallons drained, fuel quantity dropped from 1.8 gallons to 1.2 gallons.
After an additional 40 ounces drained, fuel quantity stayed at 1.2 gallons.
Total actual fuel both tanks: 5.34 gallons.
****
My calibration seemed fine but I did get the warning about the readings not changing when they really did. Here are the numbers I got:
Left Tank
971
1011
1050
1092
1094
1135
1176
1218
1301
1428
Right Tank
994
1023
1056
1098
1133
1164
1191
1248
1307
1434
When graphed, the curves track pretty well except the left tank number are a bit low in a couple of areas.
So, the fuel computer does not equal the fuel gauges which do not equal the actual gallons in the tank.
I will recalibrate the tanks this weekend (even though I'm pretty sure I did it right) but I'm not sure what to do about the fuel flow computer. Any ideas would be appreciated. I'd like some piece of mind.
I disconnected at the carb and ran each tank dry in a calibrated bucket to verify the readings. Here is what I found:
****
Fill up: 13.3 hours
Time at check: 19.0
Elapsed Time: 5.7 hours
Fuel computer reads: 2.0 gallons remaining
Left tank reads: 4.0 gallons
Actual left tank: 3.07 gallons
After 1 gallon drained, fuel quantity dropped from 4.0 to 1.8 gallons.
After 2 gallons drained, fuel quantity stayed at 1.8 gallons.
After 3 gallons drained, fuel quantity dropped to 0.0 gallons.
After an additional 16 ounces drained, fuel quantity stayed at 0.0 gallons.
Right tank reads: 4.0 gallons
Actual right tank: 2.27 gallons
After 1 gallon drained, fuel quantity dropped from 4.0 to 1.8 gallons.
After 2 gallons drained, fuel quantity dropped from 1.8 gallons to 1.2 gallons.
After an additional 40 ounces drained, fuel quantity stayed at 1.2 gallons.
Total actual fuel both tanks: 5.34 gallons.
****
My calibration seemed fine but I did get the warning about the readings not changing when they really did. Here are the numbers I got:
Left Tank
971
1011
1050
1092
1094
1135
1176
1218
1301
1428
Right Tank
994
1023
1056
1098
1133
1164
1191
1248
1307
1434
When graphed, the curves track pretty well except the left tank number are a bit low in a couple of areas.
So, the fuel computer does not equal the fuel gauges which do not equal the actual gallons in the tank.
I will recalibrate the tanks this weekend (even though I'm pretty sure I did it right) but I'm not sure what to do about the fuel flow computer. Any ideas would be appreciated. I'd like some piece of mind.