How Reliable is JPI EDM900?

[Fly Boomer]

19 minutes ago, wishboneash said:

No, I don't believe so, it isn't too hot yet here and battery/charging system all fine. It won't go past the splash screen, so I am guessing some hardware/software issue that perhaps failed some initial checks.

Let us know if you get satisfaction from JPI.

[tls pilot]

JPI is a quality company w great customer support

[wishboneash]

On 6/18/2023 at 8:56 AM, Fly Boomer said:

Let us know if you get satisfaction from JPI.

I got the unit back a few days ago. The repair charge was 1/2 an AMU for the display replacement.

Unfortunately, I get a fuel sensor error on the right main on plugging back in (ERROR R-MAIN).  I had NO issues with the fuel level sensors (which are analog, not CiES) earlier. I checked the resistance on both tanks and I am getting very odd results. This is on the P5 connector. The ground line (black) which are shorted together from both sensors is 1.1k ohms to chassis ground and the resistance from signal (white-L, green-R) to ground is over 56k ohms for both tanks! Hopefully I am doing this right. Isn't it in the 0-300 ohm range? Fuel level is about the same on both tanks and fairly low (didn't dip stick measure). I can't do much until after the holidays so troubleshooting suggestions are welcome.

[ArtVandelay]

I thought the senders were connected in series and should be 0-30 ohms, or 0-60 when connected in series. Check the other tank to make sure you’re measuring it properly.

[jetdriven]

0-60 in series.  We just installed a GI275 engine monitor.  It's nice. 

[wishboneash]

Apparently JPI had replaced the fuel board and the motherboard (besides the display) and brought it up to current standards/versions. That explains loss of all calibration data and hence the fuel level related errors. I "recalibrated" both tanks (mock re-calibration using old data) and the errors are gone. I had to update total fuel (main/aux) since those were default values and also updated the CHT warning limits which had been lost. I will do a full re-calibration as per the service manual and that will be the end of it.

[OR75]

On 7/2/2023 at 8:05 PM, jetdriven said:

0-60 in series.  We just installed a GI275 engine monitor.  It's nice. 

removed all the legacy gauges ? even fuel level ? 

picture ?

[jetdriven]

[0TreeLemur]

The JPI EDM900 fuel flow sender in our previous C model was dialed in perfectly.   It would say 43 gallons used, and when I filled it up, it took more or less 43 gallons.

In our J model, the fuel flow sensor it isn't so accurate.  Three weekends ago I flew 21 hours over three days.  Lots of opportunities to compare indicated vs. actual fuel use.   On one long cross country the totalizer said I used 50 gallons, when the actual use was 43.   Another time, the JPI said I used 56 gal. when actual use was 62 gal.  That's  +15/-9% error.  Anyone else dealt with this before?

Thx.

 

[0TreeLemur]

M20J with no factory engine gauges:

[ArtVandelay]

The JPI EDM900 fuel flow sender in our previous C model was dialed in perfectly.   It would say 43 gallons used, and when I filled it up, it took more or less 43 gallons.
In our J model, the fuel flow sensor it isn't so accurate.  Three weekends ago I flew 21 hours over three days.  Lots of opportunities to compare indicated vs. actual fuel use.   On one long cross country the totalizer said I used 50 gallons, when the actual use was 43.   Another time, the JPI said I used 56 gal. when actual use was 62 gal.  That's  +15/-9% error.  Anyone else dealt with this before?
Thx.
 

My totalizer is usually within +/- 1 gal, the overhauled factory senders less accurate, maybe +/- 2 gal, more close to full, probably because the full tanks hold a bit more than spec.

[Ragsf15e]

3 hours ago, 0TreeLemur said:

The JPI EDM900 fuel flow sender in our previous C model was dialed in perfectly.   It would say 43 gallons used, and when I filled it up, it took more or less 43 gallons.

In our J model, the fuel flow sensor it isn't so accurate.  Three weekends ago I flew 21 hours over three days.  Lots of opportunities to compare indicated vs. actual fuel use.   On one long cross country the totalizer said I used 50 gallons, when the actual use was 43.   Another time, the JPI said I used 56 gal. when actual use was 62 gal.  That's  +15/-9% error.  Anyone else dealt with this before?

Thx.

 

Mine use to be off a couple gallons each fill, but it was consistent.  There’s a procedure to adjust your k value but it won’t work if it’s not consistent.

[hubcap]

3 hours ago, Ragsf15e said:

Mine use to be off a couple gallons each fill, but it was consistent.  There’s a procedure to adjust your k value but it won’t work if it’s not consistent.

Mine was very accurate after it was properly calibrated. It would be off less than a gallon or so on a trip.

[0TreeLemur]

51 minutes ago, hubcap said:

Mine was very accurate after it was properly calibrated. It would be off less than a gallon or so on a trip.

Yes, so was the one in my C.  I dialed in a great calibration.   It changed once over the five years I owned it, and was again spot-on after recalibration.   Not sure why I'm seeing randomness in the installation in my J.  I was hoping that someone solved this problem already and could give me a hint.   The fuel pump doesn't lie.

[ArtVandelay]

Yes, so was the one in my C.  I dialed in a great calibration.   It changed once over the five years I owned it, and was again spot-on after recalibration.   Not sure why I'm seeing randomness in the installation in my J.  I was hoping that someone solved this problem already and could give me a hint.   The fuel pump doesn't lie.

I would try flushing the fuel flow sensor with carburetor cleaner and verify electrical connections are correct and secure.

[bradp]

On 1/14/2019 at 3:11 AM, Niko182 said:

I was told a lot of people do it but legally it can't be done.

Rep at Oshkosh said it can be done.  There are a few identical part numbers. 

[0TreeLemur]

On 7/7/2023 at 2:19 AM, ArtVandelay said:

I would try flushing the fuel flow sensor with carburetor cleaner and verify electrical connections are correct and secure.

Two more long cross countries and it seems to behave better.   The ff reading is very stable.   I don't think its a connection issue.   It was only installed about 50 hours ago.  I'm going to monitor it for a while longer before doing anything invasive.

[kortopates]

Yes, so was the one in my C.  I dialed in a great calibration.   It changed once over the five years I owned it, and was again spot-on after recalibration.   Not sure why I'm seeing randomness in the installation in my J.  I was hoping that someone solved this problem already and could give me a hint.   The fuel pump doesn't lie.

Randomness you describe is usually an installation issue. Make sure it’s installed in accordance with the Mooney drawing in your IPC without any 90 degree fittings (45 are okay), we’ll covered with fire sleeve and no super tight bends in hose adjacent to the transducer.


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[blaine beaven]

On 7/6/2023 at 9:04 PM, 0TreeLemur said:

Yes, so was the one in my C.  I dialed in a great calibration.   It changed once over the five years I owned it, and was again spot-on after recalibration.   Not sure why I'm seeing randomness in the installation in my J.  I was hoping that someone solved this problem already and could give me a hint.   The fuel pump doesn't lie.

On this topic… fuel pumps can lie. Unless you’re using the same fuel pump each time, your lack of consistency could be caused by a variation in calibrated fuel pump displays.