Fuel pressure weirdness DA40

Discussion in 'Maintenance Bay' started by Skyrys62, Oct 4, 2018.

  1. Skyrys62

    Skyrys62 En-Route

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    The Diamond DA40 I rent has this VM-1000 in it.
    Many times, as I'm idling/taxiing, the fuel pressure is very low (in the red) and flashing.
    Doesn't matter if the electric fuel pump is on or not.
    If I run the RPM's up past about 13-1400 it will pick up pressure sometimes. At times I have to go higher. Happens pretty consistently.
    The other day, the pressure was way high and in the red flashing.
    I took off anyway, and it leveled out appropriately.

    I reported it to the A&P but I'm not confident he will address it soon, as the engine rarely has a hiccup.. but once in a while I do notice some small 'bumps' while idling at about 1k. They are really bad when I lean aggressively, but it gets better at full rich.
    Should I keep flying?
    Have any of you seen something similar?
    Bad sensor? Electronics? Other?


    upload_2018-10-4_15-51-22.jpeg
     
  2. tspear

    tspear En-Route

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    Having had an engine shut off because of inadequate fuel pressure. I would not fly it until it's resolved most likely a sensor or setup problem but still you never know

    Sent from my SM-J737T using Tapatalk
     
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  3. Skyrys62

    Skyrys62 En-Route

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    I almost grounded the plane and called them when I was about 50 miles away.. Maybe I should to trigger the repair.
     
    Last edited: Oct 4, 2018
  4. Jamie Kirk

    Jamie Kirk Line Up and Wait

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    Plane I fly in with instructor is a DA40 also and there are times when the G1000 reads low fuel pressure and sounds the alarm on the panel. Engine never sputters nor has an issue and they have had to replace the sensor a few times.
     
  5. mondtster

    mondtster En-Route

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    Before you can make the decision that something is wrong you need to know how it should properly function. What should the instrument be indicating at various phases of flight? Does it indicate properly?

    Knowing how Diamond did their “fuel pressure” gauge in the DA-20 it would make sense for the pressure to be low during low power ground operations. The DA-40 May be similar but I am not familiar with how their fuel system is set up.
     
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  6. Skyrys62

    Skyrys62 En-Route

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    Agree...
    Myself nor anyone else that has been with me has noticed it until recently, including the CFI a long time ago.
    I would think turning on the electric fuel pump would resolve it but it never does.
    I'm waiting for an answer from the A&P but it's rare to hear from him.
     
  7. NavAir

    NavAir Pre-takeoff checklist

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    I have owned my DA40 for 17 years. Occasionally, the fuel pressure indicator on the VM1000 reads a couple of pounds lower than normal, but never lower than 18 psi. These airplanes have 2 fuel pressure sensors, the VM1000 sensor, and one that triggers the White Wire annunciator. If the annunciator did not alert, I would bet it is the VM1000 sensor. Unfortunately, that is an expensive part (more than $500). Your shop should be able diagnose it fairly easily. I wouldn't fly it until resolved.
     
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  8. Skyrys62

    Skyrys62 En-Route

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    Appreciate the input.
    I've never heard any alerts from the Diamond.
    Had to cancel a flight once because the alternator was out. There was no alert, it just showed low on the amps.