High Fuel Pressure Transients - Normal (GRT/EIS)?

[mannanj]

Originally Posted by mannanj

I've had the opposite lately. My FP has been dropping to 15-18 psi for 3-4 seconds occasionally and setting off the alarm. It usually runs 24-25 psi. I have 255hrs on a new mechanical pump.

My problem doesn't happen on short local flights. It usually happens at least once or twice on a 2-2 1/2hr leg on a cross country flight. I am always in cruise mode at 75-8500ft. VFR, no radio transmissions, just listening to my tunes on the 396 XM Radio.

I have no idea of lowering of the pressure mode as I'm usually watching for traffic until the BEEEP-BEEEP-BEEEP BEEEP goes off. When I look down both the EIS-4000 and the GRT Sport are showing 15-18psi. It always clears up, slowly creeping back up to normal. Guaranteed to get your attention though.

It was happening before my installed APRS system, so that has nothing to do with my situation.

I guess I need to talk to GRT about a new pressure transducer.

[erich weaver]

After living with transient high fuel pressure readings since first flight 1.5 years ago, I have finally figured it out and thought I would update this thread for future viewers - its some sort of fadio frequecy interference issue between my SL40 com and the fuel pressure sensor/EIS from GRT.

My high fuel pressure readings were almost always shortly before takeoff and then several times shortly before landing. I always thought it had something to do with high heat/low cooling air flow around the engine. After a flight last weekend with the typical occurrences, I asked myself "how the heck does this keep occurring right before takeoff - how could it KNOW that I am going to take off? It finally dawned on me that it knew because before every takeoff I got on the radio and announced my intentions! Sure enough next flight - 1 to 1 correspondence between radio calls and high pressure readings. Its been staring me in the face the whole time - just didnt click before. Ok, now to fix this and get rid of the flashing red light on my EFIS once and for all....

erich

[MichRV10]

I've had the same problem since I started flying my plane It only happens during transmission also. If anyone can help solve it I would appriciate it.

[Greg Arehart]

Interesting thread. I have had similar problems. I'm using the Vans FP sender going to a Dynon. Transient spikes up to 40 psi from a normal background around 22-24. When the boost pump is on, I get a rock solid 21-32 psi with no spikes. I haven't thought about the radio issue and will check to see if there is a correspondence there. I, too, would like to get rid of the red warning boxes.

greg

[fredbauerjr]

We have noticed a fuel pressure issue with our GRT EIS engine monitor also.

Our problem is that our Fuel Pressure (we have a carb) sometimes floats listlessly between 6 or 7 PSI on the high side to 1 PSI on the low side.

Our engine does not seem to have anything wrong with the engine driven mechanical fuel pump or the electric fuel pump concerning wandering fuel pressure.

Any ideas out there?