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FUEL SENDERS+JPI EDM 930


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I found out today that my bird which is in annual is going to need some new or overhauled fuel senders. When I fill the tanks the right side wing fuel guage indicates about 10 gallons low and the left side wing fuel guage indicates about 5 gallons low. Cost for everything to include labor, parts, etc. is about 1 AMU.


Now here is my question....I want to install a JPI EDM 930 at some point in the very near future. If I did this new install would I still require these fuel senders be fixed or would i recieve new hardware with the JPI EDM 930 which would then replace the old fuel senders thus saving me 1K?


My dilima is I dont want to pay to have something fixed right now that's possibly going to be replaced with something newer that's already included in the price of the JPI EDM 930


 


Thanks!

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I don't think the JPI EDM 930 comes with fuel quantity senders. It relies on the existing senders in the plane. In fact, a quote from the JPI EDM-930 installation manual...........



 


NOTE: JPI strongly recommends replacing existing fuel quantity sensors with new units.
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The 930 is wired into the factory fuel senders.  When I did research for the 830 vs 930, I was told that the 930 is a lot more oney for the install.  Basically the units cost the same to install, up to the point of the fuel senders.  They have to be wired and most installers insist on removing the senders, sending them out for repair and reinstallation before wireing in the 930.  Basically if someone installs the 930 without overhauling the sending units, the fuel tank quantity function is pointless.


I have heard that many gauges read wrong when full, but are accurate on the low side, when almost empty.  For many pilots this works ok.  I have one gauge that reads half, when full, but become accurate from half full down to empty.

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They are right unfortunately.  I have had the 930 for about a year, and am flying the plane out to willmar shortly to have new transducers installed (fuel senders) for the same reasons as you.  The 930 wires to the factory transducers.


You may have figured this out.  I currently use the "USD" function of the 930, which measures fuel used with the flow meter as the sensor.  This may need to be calibrated.  If I recall correctly there are some instructions in the 930 manual or installation manual about how to do the calibration.  Mine was very accurate when the 930 went in.  I checked and it was off on the conservative side by less than one gallon for a total usage over three trips of about 120 gallons, so that is good enough for me.  I create a table for each flight, starting with full fuel for each tank and then subtracting the fuel "USD" for that tank when I switch tanks. 


I also have one tank that reads empty when it still has about 6 gallons left.  The other tank reads accurately near empty, but declines to read full when the tank is filled.  On long range flights, it really is important to know exactly how much is left in each tank, and I don't like it when the gauge says "0" and the fuel "USD" says there are still several gallons remaining. 

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I currently have a JPI FS-450 installed and like you I count on it to provide me the most accurate data on my fuel usage.  Actually, I still do it old school and flight plan out my fuel usage and use the FS-450 to confirm what it is I actually know to already be true regarding the amount of fuel used and remaining.  There’s just something disconcerting about watching the little fuel gauge needle get close to the zero limits even when I know there’s still fuel in the tank. In any event I’m not going to fix the senders until I get the JPI EDM930 installed.  My logic is that if something is not working right with the new unit for some reason I don’t want to give anyone the opportunity to say it’s the fuel senders again.  As such, I’ll wait for whoever I choose to install the unit to work on the senders at that time

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I was going to post this in a new thread but I figured that the OP's questions on "to replace" or "not to replace" the senders and the $1K warranted some thoughts.


Please do not throw money at dead technology. 


If you pay $1k now, you WILL do it again later.  Resistive technology is d-e-a-d technology.  All "resistive" systems are prone to corrosion, varnish build up, wiper fatigue,  and the inevitable failure. 


Replace resistive technology with modern technology where/when you can.


Not meant as a thread jack but I wanted pilots to be aware of options available.


The reason people keep overhauling the floats in these aircraft is due to the FAA requirement under the type certificate and the pure lack of a better option.


However, EI offers a PMA'd, TSO'd, and STC'd sender that is built custom for each user. We call it a P-300M.  This probe works on opposing magnetics guaranteed not to loose more than 1% accuracy in 100 years.  To build we have the customer send us there old floats that need replacing.  We then build geometric copies that then drop into the factory Mooney tanks.  This probe generates a 0-5v output. Using this probe with EDM series systems may be possible.  And they cost $250.00 each at retail. (read: you'll pay less then retail)


I also wanted to ask a fairly sticky question of you folks if I may.  


I wonder what the largest variables are for you when shopping for multi function systems like the EDM-930 or...let's say...my MVP-50P?


Is it brand name alone?


Is it prior experiences with manufacturer?


Recommendations by mechanics?


Certification?


Ease of installation?


Price?


Capabilities of systems?


I am hoping for "All of the above" type of responses but I fear alot of times its maybe one or two of these items only.


I ask because there are some down right stark differences among the three brands offering a primary MFD set up for TC'd aircraft and I am trying to discover how the Pilot mind works. 


 


Thanks for letting me participate.


 


Matt



 


 


 


 


 


 


 

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When I bought my 930 you guys were the new kids on the block and unproven. Yours is a very feature rich unit.  The question was does it work as advertised.  And I am not sure you had your STC for primary available yet.  I think we pilots are skeptics on whether a thing will work and we want pireps, we are all too familiar with marketing.


A unit price comparison does not help us much, because most of the cost is going to be installation, not the cost of your unit or JPI's.


I really like what you said about your fuel transducers, they are way cheaper than the factory one's, except the part where they may  work with an EDM.  My A & P won't install a unit that may  work and I won't let them.  When you fly, you have to treat everything as though it is trying to kill you.  Putting in a fuel transducer that may work, or then again may decide at some point it does not want to cooperate with others, is not a comfort when one is overflying the Rockies, or Lake Michigan, or having to make multiple approaches in IMC.  May have enough fuel to do it is not good enough. 


Don't mean to be critical though.  You all seem to have done a good job of getting the word out about your display, and there are now some favorable pireps.  If I were buying now, I would certainly give it some serious thought.  We like having alternatives and competition in the market.  We need good sources of replacement parts now more than ever. 

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Thank you very much for the feedback.


The MVP's STC was issued 4/17/2009 so I do very much understand the timing.   


I looked a bit further into the issue and there appears to be a compatibility issues that would need to be addressed if the P-300M was to be used with the EDM-930.  A.  Can they supply a 5v + to the sender? and B. Can they calibrate to a 0-5v signal?


The next consideration would be the paperwork.  How would the P-300M be documented, probably requiring an individual 337 approval.


Matt

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"I wonder what the largest variables are for you when shopping for multi function systems like the EDM-930 or...let's say...my MVP-50P?"  Matt


 


Matt,


This is a very interesting question that is deserving of it's own thread.  Would you please consider relaunching it on it's own with a poll as you have outlined your individual categories. 


Please include the little fish as a response in the Poll.


Best regards,


-a-

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Quote: 201-FLYER

I currently have a JPI FS-450 installed and like you I count on it to provide me the most accurate data on my fuel usage.  Actually, I still do it old school and flight plan out my fuel usage and use the FS-450 to confirm what it is I actually know to already be true regarding the amount of fuel used and remaining. 

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Same as my 930, it has the same functions.  You do need to calibrate, but you feel alot better when you know where you are fuel wise to a few tenths of gallons.  It even gives you an MPG number.  Don't know that I really want to look at that on a headwind day though.

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