Here you can find a fuel pressure sensor having a gauge and an alarm outlet pin:
See the calibration test result below.
The alarm sensor part switches on below 0,8 bar. (useful to lit "oil-pressure-too-low" indicator lamp)
Another type fuelpressure_sensor:
Its calibration curve is linear:
This is not absolute pressure, but relative to athmosperic. So 5bar measurement range means (1 bar athmosphere) + (for example):
- 2 bar boost + 3 bar fuel pressure (above MAP)
- or 1.2 bar boost + 3.8 bar fuel pressure (above MAP)
Fuel pressure sensor connection
- GND - resistive pressure sensor - 270 Ohm pullup - 5V (EC36pin28)
- the signal from the sensor (not the GND but the other end, of course: that has the pullup) connected to an analog input: EC18pin6, 12 or 16 depending on your ECM configuration, see text for assembled controller in WebShop
- 1.0.36 firmware can log the MCP3208 signals (as 0..5V) to MegaTune
- try to take note of the real pressure and real voltage (just for verification) to be compared to the readings in the log
- conversion table (voltage to real pressure) will be added later (don't forget to publish on your project page the type of sensor used!).
- propose a position on the 4x20 LCD for the fuel pressure (maybe instead of the iac RPM target on the bottom right part of mlp00 ?)