Tacho and fuel flow readings off the scale EMS10

[Henrik]

Hi Guys,
Hope you can help. On start up the RPM reading went straight to 999, and fuel flow to 99GPH. Occaisionally, the tacho will drop to 0 and then a minute or two later go to 999 again. Have also noticed that at min throttle setting the Tach reading drops a little to about 890 / 900.
Other readings Man pres., fuel pressure, etc all normal. Have tested sensors and checked connections forward of the firewall...all seem to be properly connected. VP working ok, and we are not consuming 99GPH!
Look forward to any thoughts,
Henrik

 

[dynonsupport]

Re: Tacho and fuel flow readings off the scale EMS

Henrik,

That is weird.

The RPM and fuel flow are the only two frequency measurements in the system, but that's about the only way I can think they are related.

When you say 999 on RPM do you mean 9999? There are 4 digits displayed, so just trying to figure out what exactly it is showing.

When you say "on startup" do you mean with the engine running, or just with the EMS on? Does it read this way with the EMS on and no engine running?

How is your tach hooked to your EMS? P-leads, alternator, pickup, ???? What kind of engine?

Finally, what software version are you running?

 

[Henrik]

Re: Tacho and fuel flow readings off the scale EMS

lots of info missing...appologies:
On firing up Dynon "0"
on engine start up "9999"
Engine Superior (Lycoming) XP-I0-360-B1AA2
Take off P leads
Version 01.02
Having now checked connections forward of the firewall, we intend to hook up a lap top and see if that gives any feedback. But not having installed the kit ourselves, and with no practical knowledge of the kit other than flying it, we felt it best to contact you first. Guidance much appreciated.
Henrik

 

[Henrik]

Re: Tacho and fuel flow readings off the scale EMS

Hi,
I have now updated firmware to latest version, from your website.
back up available if this will help.
Unfortunately no change.
have checked configuration: puls/rev: set to 1
if the settings are adjusted to 8 pulses per rev, reading drops to figures in the region 4000.
Fuel flow also reduces.
Your further comments would be appreciated.
Henrik

 

[dynonsupport]

Re: Tacho and fuel flow readings off the scale EMS

Henrik,

When connected to the P-leads, a 30K-150K ohm resistor is required between the P-leads and the EMS. We supply this in our install kit. the exact value is not important.

I'd check and make sure the installer put these resistors in. The EMS will behave poorly without them, much like you are seeing, so it sounds like they might not be there. They are also an important safety item.

The laptop won't show you any more data than is on the screen, so that won't help you much.

 

[Henrik]

Re: Tacho and fuel flow readings off the scale EMS

Hi,
Thanks, these are in place and tested as working.
Henrik

 

[Henrik]

Re: Tacho and fuel flow readings off the scale EMS

ANY OTHER IDEAS OR HELP?

 

[dynonsupport]

Re: Tacho and fuel flow readings off the scale EMS

Henrik,
Sorry, we assumed that last post meant everything was working!

Unfortunately, we don't have any other ideas. We've never heard of an engine setup doing what you describe, so it's hard for us to come up with any other ideas.

If it were my plane, the next thing I would try is disconnecting the P-leads from the EMS completely and seeing if fuel flow works and if the Tach stays at zero. If that works, then we at least know to focus on the RPM leads.

 

[dynonsupport]

Re: Tacho and fuel flow readings off the scale EMS

Also, try measuring the resistance of those resistors to make sure they're actually the 30K ones. We also send you a few other resistors in the 1K range with the EMS.

 

[Henrik]

Re: Tacho and fuel flow readings off the scale EMS

Thanks. We have already tested the resistors but will do so again. If we have no luck with this, could we send the unit back to youand can you provide a loan unit whilst we are unable to use the existing? Will gte back to you with the results of testing as soon as time permits.

Henrik

 

[Henrik]

Re: Tacho and fuel flow readings off the scale EMS

Good Morning Dynon,
We have now tested the unit with the P leads disconnected...
Tacho reading "0"
Fuel flow still up at 99 GPH at tick over.
We then reconnected the P leads and replaced the exisiting resistors with new 100k ones.
The readings have then reverted to same as before....
Tacho straight to 9999 on starting engine and fuel flow building up to 99gph.
It is probably also worth noting that the unit is  now vey slow to boot up.
This seems to have deteriorated over the period we have been testing....
20 or so seconds to see the blue Dynon screen and logo.
then another 1 min 10 seconds the sceen blacks out and
then another 1minute 25 seconds the full instrument screen comes on.
The buttons also seem "sticky." Sometimes tacking two or three pushes to operate the action requested.
We really can not loose any more time.
Could you confirm availabillity of a replacement unit Urgently?
I look forward to some feed back as soon as possible,
Henrik

 

 

[dynonsupport]

Re: Tacho and fuel flow readings off the scale EMS

Henrik,
I know you called when the site was down, I just want people to know this has been dealt with.

The key here was that the clock was way off- the EMS thought 20 real seconds were 1 second, so when it saw a bunch of pulses in those 20 seconds, it thought that was 9999+ RPM. Sorry for your trouble and we'll get it fixed ASAP.