Oil pressure too high with Kavlico 150PSI

[hagendav]

Hello dear Dynon support,

I upgraded from an EMS D10 to a Skyview system. Doing this, I got an erratic manifold pressure and too high oil pressure ( VDO probe for oil pressure).

I changed the manifold probe to the Kavlico as well as for the oil pressure.
Manifold pressure is now fine but oil pressure is still too high, showing up to 110 PSI. An external mechanical oil pressure probe shows a correct pressure. The new probe is connected to pin 16, +5V from pin 18 shared with Manifold pressure and ground.

What is wrong?

Thank you for your help and advise.

David :-/

 

[Dynon]

I think we might be looking at a wiring issue here. Assuming you don't have a type-o above, pin 16 is ground, not signal, so if you have that connected to the kavlico signal wire, that could cause issues. The signal wire should be going to any of pins 4, 6, 7, 8, 9, 10, 11, 12, 20, 21, 22, 23, or 31. Usually it's pin 6 if you go by the manual recommendation. Beyond that, assuming your oil pressure sensor is responsive (and isn't just sitting at 120), what does the entire row of the pin mapping page have for the oil pressure row listing?

The MAP can't use a Kavlico sensor (I'm pretty sure, anyway), so I think you mean that you replaced that with a new one?

 

[hagendav]

Thanks for the answer.

I apologize, it is not pin 16 but 6. The sensor is responsive, showing 0 when engine is still, 77 when running with 1000 rpm and over 100 when in flight (2350 rpm).
The MAP is the new one, you must be right, maybe not a Kavlico but the MAP is now working well. The oil pressure is also the new one, with a special 3-pin plug (black-red-green wire).

Any idea?

Thanks
David

 

[hagendav]

I will come back to you ASAP with the pin mapping page and oil pressure row listing.

Regards,
David

 

[jakej]

David

"An external mechanical oil pressure probe shows a correct pressure"  -- is the mechanical one showing same as Dynon or is it different ?

Kavilico  - red wire to 5v, green to pin 6 & black to Dynon ground wire ? 
Then go to the Sensor Setup Menu (SETUP MENU > EMS SETUP > SENSOR SETUP) to manually configure the settings of an EMS sensor.

 

[hagendav]

Hi,

The external probe (a hydraulic probe from a certified engine maintenance workshop) showed a pressure of 80 psi on high rpm, as the Dynon shows 102 (in the red range, based on the Lycoming definition range). The engine is a O320-E2A (150hp). The wires are connected as you say. The previous probe (VDO) showed the same high value. Is it possible that the problem comes from a bad ground as I read in other articles of the forum or is it possible that the probe definition file is corrupted in the Skyview? The VDO probe was working well with the EMS D10 and I changed it, buying the new one to be sure that it will fit to Skyview requirements.

 

[jakej]

I find the safest method is to use a ground wire that terminates in the Dynon connector, you can parallel the one from another sensor if you wish.

 

[Dynon]

The fact that you have two different sensors with two different characterizations reading equally high is odd. Grounding can definitely cause issues, but, it's oil temperature that is more sensitive to grounding, and not so much on SkyView. After checking the pin mapping, also grab, from the sensor debug page (under EMS setup) the entire first row, which has information about the sensor definitions on your system. Taking a picture of that would be useful. And also on the sensor debug page when operating - and you're seeing the readings that are too high - what does the entire row for oil pressure say?

 

[hagendav]

I will check this the weekend and come back to you on Monday.

 

[hagendav]

Hello,

I took some photos from the debug screen. In between, I added a ground wire directly from the Dynon black ground at the probe to the battery and the engine. I can confirm that all probes are now very stable, including the MAP, but the oil pressure is still too high, showing 105 PSI instead of around 90 as the hydraulic analog instrument showed.

Here are the photos I took.
Do you think the configure file could be wrong or can we make an new one, adapted to my probe?

I will ask the engine maintenance workshop for the exact values noted at the last check with the analog instrument for each RPM (2000/2200/2300/2400).

David

 

[Dynon]

So the characterization for that sensor is right. For the voltage that the sensor is outputting in that picture, you should indeed be seeing high nineties (for that particular picture). It looks like you have another 150psi sensor (the VDO style) in there for fuel. You said you've changed them to test, and the VDO also reads high. Is that correct? If so, does it read a similar value to the Kavlico? If it does, because those sensors work so differently, it's not likely that either SkyView or the sensor is faulty.

 

[hagendav]

For the fuel pressure, I didn't change the probe. It is still the one which was delivered from Dynon with the EMS-D10 at least 6 years ago. The indicated values seem to be correct.

For the oil pressure, I had the one provided by Dynon with the EMS-D10 and due to the fact that indicated pressure was too high, I supposed that it was not reacting well with the Skyview. Therefore, I asked the french re-seller FinessMax to give me the one that they sell with the Skyview. The result is the same and nothing changed.

 

[Dynon]

This STRONGLY indicates - because those sensors have different principles of operation and have different voltage output ranges - that the reading you're getting is correct.