vdo oil pressure

[Fracrat]

cannot seem to get oil pressure reading correctly. with engine not started, pressure reads 75 psi. in flight 125psi. i have installed the resistors and believe the case is grounded since it is installed on firewall. i have 5400 efis with 320 lycoming, non injected. any guidance is appreciated.

[neville]

you might check the wiring. When I installed the VDO sensor on my Rotax engine I used the wiring diagram included with the sensor. Oil pressure readings wrong. Sent the sensor back to Advanced for testing, sensor OK. Then looked up diagram in Advanced install manual and discovered the diagram sent with sensor had two wire connections
reversed. Re wired, all OK.

[Shawn McGinnis]

If you remove the wire from the VDO sensor do you measure ~5volts?

Have you configured your display to use the VDO sensor table settings?

309

[SDClark]

If you remove the wire from the VDO sensor do you measure ~5volts?

Have you configured your display to use the VDO sensor table settings?
While it appears that this is a new installation, I think the VDO sensors can be flaky. Mine has operated ok for 3 years (no clue if the values have been accurate). Recently, however, the sensor has started intermittently reporting pressure of 100 lb+ when I power up the my 4500 prior to engine start. A minute or so after engine start the pressure drops to reasonable values and stays at reasonable values throughout flights. FWIW, I've also seen, on rare occasion, the VDO fuel pressure sensor peg on power up.

[Fracrat]

If you remove the wire from the VDO sensor do you measure ~5volts?

Have you configured your display to use the VDO sensor table settings?

Good Morning Shawn, Yes the efis is configured for vdo sensor and i have used several different values to try and adjust the readings. nothing worked. have not checked the voltage at sensor however. will do so today. thanks.