silviobruschi
New Member
- Joined
- Oct 20, 2008
- Messages
- 8
Good morning to all,
instrument just installed. D-180 + Jabiru 2200 inst. package purchased from aircraft spruce. Low readings from fuel pressure. Fuel pump changed, still low readings. Checked by analog mechanical press gauge, readings were o.k. Sensor is type 1 (100411-000 for carburated engines). It goes from 0 to 2 bar. Sensor is connected to pin 8 (brown) on DB37 and to one of the black wires (ground) coming from DB37 and is mounted on the firewall (no engine vibration allowed). So I performed a sensor pressure test. Pression was given by a liftable water column from 0 to 500 cm. height (0-0.5 bar pressure) in steps of 50 cm. (0.05 bar steps). Pressure confirmed by mechanical analog gauge too. Digital ohmmeter connected to the terminas of the sensor. Total of two sets of measurements: the first increasing the pressure from 0 to 0.5 bar, the second lowering the pressure from 0.5 to 0 bar. Results as follows:
Pressure (bar) ohms (increasing press.) ohms (decreasing press.)
----------------------------------------------------------------------------------
0.00 11.0 | 11.0 ^
0.05 10,9 | 11.0 |
0.10 10.9 | 13.0 |
0.15 11.2 | 17.3 |
0.20 17.4 | 23.7 |
0.25 21.6 | 28.0 |
0.30 28.2 | 36.6 |
0.35 36.6 | 41.1 |
0.40 38.7 | 47.3 |
0.45 43.1 | 47.7 |
0.50 49.4 V
Ohmmeter reading shows that the sensor has a very pronounced hysteresis starting from 0 going up and also when pressure goes up and down. Is this a bad performance of my sensor, or, due to the very small pressure inteval permitted for Jabiru (0.05 to 0.2 bar) this is common to all sensors? This would make the fuel pressure gauge unusable for Jabiru. Thank you for a kind answer.
Another question:
I connected the two power pins (pin 1 of DB25 and pin 1 of D3B7) together and to the 12V. Reading the forum (and then page 2-8 of the manual) I see that only the DB25 requires power. Is it mandatory to disconnect DB37 from 12V power, or I can let it connected?
Thank you very much for answers. Greetings from Italy!
instrument just installed. D-180 + Jabiru 2200 inst. package purchased from aircraft spruce. Low readings from fuel pressure. Fuel pump changed, still low readings. Checked by analog mechanical press gauge, readings were o.k. Sensor is type 1 (100411-000 for carburated engines). It goes from 0 to 2 bar. Sensor is connected to pin 8 (brown) on DB37 and to one of the black wires (ground) coming from DB37 and is mounted on the firewall (no engine vibration allowed). So I performed a sensor pressure test. Pression was given by a liftable water column from 0 to 500 cm. height (0-0.5 bar pressure) in steps of 50 cm. (0.05 bar steps). Pressure confirmed by mechanical analog gauge too. Digital ohmmeter connected to the terminas of the sensor. Total of two sets of measurements: the first increasing the pressure from 0 to 0.5 bar, the second lowering the pressure from 0.5 to 0 bar. Results as follows:
Pressure (bar) ohms (increasing press.) ohms (decreasing press.)
----------------------------------------------------------------------------------
0.00 11.0 | 11.0 ^
0.05 10,9 | 11.0 |
0.10 10.9 | 13.0 |
0.15 11.2 | 17.3 |
0.20 17.4 | 23.7 |
0.25 21.6 | 28.0 |
0.30 28.2 | 36.6 |
0.35 36.6 | 41.1 |
0.40 38.7 | 47.3 |
0.45 43.1 | 47.7 |
0.50 49.4 V
Ohmmeter reading shows that the sensor has a very pronounced hysteresis starting from 0 going up and also when pressure goes up and down. Is this a bad performance of my sensor, or, due to the very small pressure inteval permitted for Jabiru (0.05 to 0.2 bar) this is common to all sensors? This would make the fuel pressure gauge unusable for Jabiru. Thank you for a kind answer.
Another question:
I connected the two power pins (pin 1 of DB25 and pin 1 of D3B7) together and to the 12V. Reading the forum (and then page 2-8 of the manual) I see that only the DB25 requires power. Is it mandatory to disconnect DB37 from 12V power, or I can let it connected?
Thank you very much for answers. Greetings from Italy!