Problems with multiple sensors... if the EM2 is good, a bad (high resistance counts-) ground is a huge suspect. It doesn't have to be bad all the time. You could even have a ground loop, where you have multiple return paths for current. That can throw all kinds of sensors off. That's still a bad ground even if it tests good on the ground.
My advice, such as it is: the Dynon is great and I'm installing one myself... but a temp sensor is pretty simple. Again assuming the EMA tests out good (has Tracy had a chance to test it out?) You'll probably have the same problems. Might be good to find the issue first. Maybe try an old-school gauge for a bit just to prove the point? I don't know how well the EMA is protected on its inputs... but suppose it's just barely tolerating something that would fry the Dynon completely?
On Sep 13, 2011 7:13 PM, "Chris Barber" <
cbarber@texasattorney.net> wrote:
> I have not spoken with Tracy about the latest issue as I try to leave him alone until I exhaust other avenues, including y'all first. I imagine he gets pretty overwhelmed at times.
>
>
>
> As to the EGT issue, I have sent the unit back to Tracy and it got a good check up. I THINK I have tried the things suggested and I have checked the d-sub, grounds, wires etc until my eyes are crossing and I start shouting "French" at inanimate wires and connections. Yeah, real mature...and I am trying to build an airplane...YIKES.
>
> ________________________________
> From: Rotary motors in aircraft [
flyrotary@lancaironline.net] on behalf of Mark Steitle [
msteitle@gmail.com]
> Sent: Tuesday, September 13, 2011 5:45 PM
> To: Rotary motors in aircraft
> Subject: [FlyRotary] Re: EM2 problems
>
> Chris,
>
> Have you spoken with Tracy? I suspect he will have some good suggestions. My guess is wiring, especially in relation to the H2O sensor. I would take a real close look at the EM-2 d-sub connector for solder bridges or cold solder joints. Also, I would check ground between the EM-2, engine and battery with an ohm-meter. And finally, I would double check that something isn't cross-wired.
>
> Mark S.
>
> On Tue, Sep 13, 2011 at 5:37 PM, Chris Barber <
cbarber@texasattorney.net<mailto:
cbarber@texasattorney.net>> wrote:
>
> OH, and when I use my handy dandy hand held thermal gage from HF, I am getting the same temp as the reading when the engine is not ruining, thus something is happening when I start up. OH, btw my engine is not overheating. Like I mentioned, even at 100 degree days, the temps are down significantly ...it is the EM2 readings that are off....unless I can run my engine at 270 degrees with no boil over.
>
>
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> Other than this, currently the engine is running GREAT. (yeah, I know, famous last words....especially with my history....DOH!)
>
>
>
> Chris
>
> ________________________________
>
> From: Rotary motors in aircraft [
flyrotary@lancaironline.net<mailto:
flyrotary@lancaironline.net>] on behalf of Chris Barber [
cbarber@texasattorney.net<mailto:
cbarber@texasattorney.net>]
> Sent: Tuesday, September 13, 2011 5:28 PM
> To: Rotary motors in aircraft
> Subject: [FlyRotary] EM2 problems
>
>
> I have posted in the past with problems regarding my EM2 giving me wildly inconsistent reading with my EGT's. The reading flash to randomly increasing numbers up to readings of 9000 degrees. I replaced the EGT sensors and all wires/thermal couplers to the EGT to no avail. The consensus has been "noise" especially since the EGT are so low voltage. I have now run the wirers along the outside to the plane away from all other wires and still no joy.
>
>
>
> NOW, I am having strange readings with the coolant temperature. I have not changed anything, no movement of wires etc...well, at first, I have now replaced the sender with no change. What seems to be happening is that when the engine is not running, the coolant temperature seems about right (which is pretty close to the oil temp....my oil temps dropped quite a bit after finally getting my oil pressure up with a new front cover O-ring). HOWEVER, when I start up the engine the coolant temperature reading shoots up anywhere from 50 to 100 degrees higher than before I start and/or immediately after I shut down (thus not enough time to cool). It is also about the same amount higher than the oil reading. I have removed the wire from the bundled harness to minimize interference.
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>
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> I am suddenly also having an issue with the coolant pressure reading flashing to "N" intermittingly (I am guessing similiar to the NOP on the tach). I too have checked the wires. Nothing has been changed, the coolant temp and pressure just started happening...the EGT has always been a problem. Again, I have now replaced all the sening units and wires.
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>
>
> Ok, while the EGT may be somewhat secondary in use, the coolant temperature is not. I have tried various wires. Moved wires and replaced all sensors and re-did D-sub pins.
>
>
>
> Thoughts?
>
>
>
> I am about two minutes away from ordering the Dynon engine monitor( which I intend to buy eventually anyway), however, I am not thrilled at the idea of throwing money at what may be a simple fix...and may still have problems with even with the new unit.
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>
>
> Thanks.
>
>
>
> Chris
>