[November 19, 2016]

Over the last few flights, I have noticed my fuel pressure creeping higher. I was almost certain this was a sensor issue, as I would get high fuel pressure whether I had just the electric fuel pump running while on the ground, or just the engine driven fuel pump.

This is the second VDO sensor I have installed for the fuel pressure. It's common for these to fail, and GRT doesn't even sell this as an option for a fuel sensor anymore.

Instead GRT has switched to the SSI solid state pressure sensor. It is a little more complicated to install since it required three wires (power, ground and signal), whereas the VDO sensor only had a signal wire.

A close up of the exact model number - SSI Technologies P51-100-G-B-I36-5V-000-000. This guy cost about $150, which is significantly higher than the VDO sensor, which ran about $40-$50.

GRT brands this sensor has the "HPS SS-01".

Installing the sensor was somewhat easy. Out with the old and in with the new!

The more complicated portion of the installation happened under the panel, where I needed to remove a biasing resistor used with the old sensor, and wire in the power and ground wires with the new sensor.

After configuring the sensor, it seemed to read a much more believable fuel pressure - 33 PSI.

My #2 CHT sensor has been acting somewhat erratic over the last few flights - ever since my Labor Day trip to Chicago. I ordered a new CHT sensor from GRT and swapped it out while I had the cowling off.

I also checked out the valve clearance with the valve guide. This cylinder had a sticky exhaust valve last year, so I seriously doubted the issue returned in less than 100 hours. Luckily everything checked out just fine. I ordered a Borescope to take a look inside the cylinder just to be 100% complete.



Last Modified: May 19, 2024