High indicated fuel pressure - UPDATED

[cbennet12]

Hi,

Since replacing my engine driven fuel pump I am seeing fuel pressure readings of 13-14 PSI - versus the 4 PSI expected.  I connected a mechanical gauge to the line and it reads 3-4 PSI. I found an older 0-80 PSI transducer which indicates 4-5 PSI so it is definitely a issue with the transducer.

My transducer is less than 2 years old, is there anything that can be done with it or do I just need to spend $80 for a new one?



Thanks,
Craig

 

[TRCsmith]

Re: High indicated fuel pressure

You better check the part number on the fuel pump, it sounds like you have the wrong fuel pump. Assuming you haven't done anything else to your system.

 

[cbennet12]

Re: High indicated fuel pressure

Thanks for the suggestion but as I indicated my Aux pump also indicates high w/o the engine running. I also just used a mechanical gauge and it reads 3-4 PSI. NO doubt now that it is an indication problem.

Craig

 

[skysailor]

Go into the sensor definitions page and make sure the fuel pressure sender indicated is the one you actually have installed. I had the same thing happen. The page showed the 0-80 PSI sensor listed instead of the lower pressure carb one. That gave the incorrect reading. I had verified the correct pressure with a known accurate mechanical gauge as well. Changing the sensor listing to the correct listing (matching the one actually installed) solved the problem immediately.

 

[Garrett]

It sounds like the transducer to me. You can find a new VDO sending unit on Amazon.com for about $30.00.

 

[Dynon]

Did the same transducer work before the upgrade? Which one is it, by the way? The older VDO style (silver bell), or the newer Kavlico ones (smaller / thin / gold-colored). Did you make any changes to the Dynon sensor setup at the same time? Also SkyView or a D10/D100 series product?

 

[cbennet12]

Sigh. The good news is that changing the EMS setting from 0-80 PSI to 0-30 PSI to match the transducer installed corrected the problem. (Dynon: I have the twin connector version of the transducer)

The bad news is I have no explanation as to why it was wrong since I do not ever recall seeing high pressure readings in the last two years - only sine replacing the engine driven pump.

I can only assume that it was wrong since installation and my old pump was so weak it was indicating low for some time. This doesn't explain how I never noticed a high reading when the Aux pump was engaged (it now indicates correctly of course).

Once again I am reminded to check all of the simple things first.

Thanks to all for the feedback.

Craig

 

[rswalden]

I had the same problem with my older style (one wire) fuel pressure sensor that would every once in a while shout out a "high fuel pressure" warning.

Seems this is a common problem with the older style mechanical pressure sensors.

I replaced both of my fuel pressure and oil pressure sensors with the newer solid state Kavlico sensors and haven't had a problem since.   You'll have to run the Dynon +5 exciter voltage from your Dynon EFIS/EMS unit (if that's what you're using) through the firewall to the transducers, but beyond that, it is a straightforward swap that I'm guessing will cure your problem.

Best wishes,
   Bob Walden