High Fuel Pressure Warning

There is no need for "Pulling Half the Plane to Bits".
Remove the suspect Hose from the 4-Way Connector on top of the engine.
Somewhere between the hose and the 4-Way Manifold, there should be an "Orifice".
It is usually contained within the Hose fitting.
You are looking for something that blocks the fuel flow except for a Very, Very small hole.  (~0.015")

If the fitting looks to be plugged, Blow some air into it to dry it out.  Do not go poking at it!
Then shine a strong light through the fitting.
You should be able to see a Pin-Hole-Sized point of light shining through.

If you have an Orifice in the fitting, you have a return line!

While the hose is OFF, Blow some Air into it and see if you can hear it escaping inside the fuel Tank.

- - -

Your Airframe Manual may be slightly out of date.
The Return line on the ULS engine is a recent addition and the manual may not reference it even though it appears that you have it.

In either event, you do Not have excessive Fuel pressure.
The Electric AUX pump is capable of over-boosting the pressure but the Mechanical pump can not.
Then operating Both pumps together, your pressure will be the higher of the two, Not the Sum of the two.

Thanks everyone for your input - It is much appreciated, and why I love this site.

OK. UPDATE...

Bristell have confirmed the line is a return line, and it runs back to the left tank.  They also confirmed that the manufacturer of the fuel sensor (Kavlico) have confirmed that there are some issues with fuel pressure when descending, and it's a known bug.

All good.  I will up my pressure alarm above, and keep smiling!

All -

I saw this string and it is close to my concern experienced yesterday with high Fuel Pressure.

Just completed the 5 year rubber replacement which included new Mechanical Pump (893-115), new Facet Elec. Pump, and new UMA T1EU07 Fuel Pressure Sender (0-7psi).

For about the first 3 hours since the above work, my fuel pressure indicated about 4.0 to 4.5 psi without Elec Pump which seems to only add about 0.5 psi.

Yesterday, I started out about 4.5 psi, upon reaching cruise at about 5000RPM. After about 20 minutes, I received High Caution and even High Alarm Fuel pressure from my MGL EMS. (Understand that my High Caution is set at 5.5 and High Alarm is set at 5.8 psi with display set for 0.1 to 10.0 psi.)

My readings continued between 5.5 and 5.9 psi for remainder of flight until shutdown on ground which was total time of about 25 minutes.

I understand, from reading these posts, that the maximum FP is now 7.26 psi instead of the old 5.8 psi.

I don't understand why for almost 3 hours, readings were less than 5 psi at all times, but now went to mid to high 5 psi readings. Unless it took a few hours to get rid of any air that might have been in the fuel lines.

Do I have a an issue or does this appear to be normal?