High Fuel Pressure After Start

So I may have jumped the gun here.  Looks like other threads recommend taking a manual pressure reading to ensure the sensor is calibrated properly.  I'll do that first and report back to this thread.  I'm using the Stock Flight Systems EMU with the Rotax issued fule sensor (664365).  It looks like the EMU supports a fuel pressure offset adjustment so I'll verify with an analog pressure gauge first and make changes if required.

Tim

The Bypass Orifice has nothing to do with the fuel pressure.
You could eliminate the bypass and the fuel pressure will not change.

The fuel pressure regulator controls the pressure at 3 bar (~44psi) above (Differential) the Airbox(MAP) pressure.
If the Fuel RETURN (Not the BYPASS) Hose is restricted, the measured fuel pressure will increase.
If the Fine fuel filter is restricted, the measured pressure will increase.

Measure the Fuel pressure before the Fine Fuel Filter and at the Fuel Manifold Input.
Both should be within 1 psi of each other with a New, Clean, Fine Fuel Filter.

A Mechanical Pressure Gauge should indicate a fuel pressure of ~35 psi (Gauge) with the engine at idle.

The numbers you are seeing are consistent with an ABSOLUTE Fuel pressure measurement.
The Fuel pressure needs to be a DIFFERENTIAL Measurement.

You just got to love Bill. He has some great info.

Thanks for he recommendation and I'll try that today if I can  find a test gauge in town.  If not, I'll need to order something online.  Any suggestions of the fuel pressure test kit to get?

Also, spoke with Michael Stock at Stock Flight Systems as this is the EMU I'm using.  He had me measure the voltage across the sensor connectors and it would appear I'm getting a slightly higher voltage than normal on the output contact (2.2 volts at 1 Bar ambient).  At least that was my interpretation from the voltage vs pressure chart he sent me.  My interpretation may be all wrong so I'm waiting to hear back from Michael.  I did play with the offset on the EMU yesterday and verified I can make adjustments to get the numbers within the proper range but obviously I need to know what the 'actual' pressure is before doing this.

Thanks!

The test gauge is nothing special.
You can Redneck it out or Hardware and Auto Parts store Pieces/Parts.
Any 100psi Gauge and a few odd fittings to tap into your lines will do the job.