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Kavlico Sensor setup question...

rvanstory

rvanstory

Well Known Member
Have my engine and panel in and wire getting ready for first ground runs. I have a Garmin G3X and have a question about the Kavlico sensors (NOT related to the leaks some have had). All other engine sensors (CHT, EGT, etc...) are reading based on current "no run" conditions. (i.e., CHT temps read outside air temps). However, I expected the Fuel Pressure, Oil Pressure to read zero and Manifold Pressure to read barometric pressure. With no engine fired up, the Fuel and Oil pressure gauges are reading 47 and 83 and manifold pressure is reading around 31.

Is this normal? Will they read "correctly" after engine start? Did others experience this too?
 
Fuel and oil pressure are obviously wrong, go to the configuration menu and verify the G3X is configured for your sensors. The MP reading sounds correct, it should read ambient pressure for your location. (29.92 inches std. day sea level).
 
Jpm757 said:
verify the G3X is configured for your sensors.
Click to expand...

I have confirmed the correct sensors in setup page and that the correct sensors were installed correctly (right sensor for fuel & oil) on the firewall side of things.
 
G3X

If you go into the config page, you should be able to see what voltage the G3X is sensing from the probes. The GEA24 outputs a reference voltage of +5v or +12v depending on the pin, to the sensor, which returns a value between 0-5 or 0-12 based on pressure.

If you are near those limits, might you have reversed to signal and reference voltage pins?
 
rocketman1988 said:
If you go into the config page, you should be able to see what voltage the G3X is sensing from the probes. The GEA24 outputs a reference voltage of +5v or +12v depending on the pin, to the sensor, which returns a value between 0-5 or 0-12 based on pressure.

If you are near those limits, might you have reversed to signal and reference voltage pins?
Click to expand...

The kavlico transducers get a 5 volt power source and returns, linearly, .5 volts at 0 PSI and 4.5 volts at max (50 / 150 PSI). I suspect that maybe you fed them 12 volts instead of 5 volts. Most G3X sensor inputs have both a 12 and 5 volt source pin; installer picks the correct one. Maybe you used the wrong one? The sensor doesn't have a sophisticated power supply able to deal with variable voltages; it just divides/reduces the source voltage for the return. Therefore, I would expect numbers similar to yours with a 12 volt feed. Oddly the fuel is almost 100% and the oil is 50% or rated. If I remember correctly, the MAP sensor uses 12 volts and would explain why it is working correctly.

Larry
 
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