intermittent faulty readings

[HRII_Pilot]

Where do I start. I have had My D180 on my HRII for 27 hours now and am having some intermittent faulty readings. The problems starting occuring arround hour 15. I am not sure the unit is the problem. I am in hopes that someone in the forum will have some suggestions. The problems are:
Fuel Flow will go from 16gph to 0 then back to 16
Low current alarm. reads -99amps then slowly climbs back to +2amps
High EGT alarm. all 6 cyl. jump to 1500+ then decrease to normal
High fuel pressure alarm
Low fuel pressure alarm
High oil pressure alarm
low oil pressure alarm

These alarms are very random but always start with the fuel flow going to 0 and progresses to the others. They also do not occur till 5 to 10 minutes after takeoff. Makes me thik it is heat related. I have checked all electrical connections including the grounding system and all are good. Per Dynon tech support, I physically removed the fuel flow to see if it was the source of my problem. It wasn't. With the unit acting up, I switched off the breaker to the unit and ran it on battery to see if the alternatior was the problem. It wasn't. I'm out of ideas and any suggestions would be greatly appreciated.
thanks
ken

 

[dynonsupport]

Does everything go haywire together, or is it a one at a time sort of thing?

A few things to check:

Do you have the 30K resistors installed on the tach lines (if you're connected to conventional mags)?
Check that neither the EMS's 5V output nor the 12V output are going anywhere they shouldn't be going.
Are all the sensors you're using ones obtained from Dynon?

 

[HRII_Pilot]

It is one at a time sort of thing. always starts with fuel flow then progresses to others. The tach is read off the p-leads with a 30 ohm resister on each switch.

All sensors are from dynon.

I believe the only +5 volts I am using are for the MAP which is working fine and the only +12V I am using is for the Fuel flow and that is currently removed with each wire capped off. The harness is also from Dynon. I have not checked any connections at the plugs, but I have gone thru all my connections. All were crimped, soldered then heat shrinked. All ground connecitons for every device are grounded at one location on terminal strip. I am planning on changing the alternaor this weekend to see if that is the problem. If you look me up in your data base you can look at my history with this unit. This is actually the second unit. Dynon replaced the first unit at hour 16 when it showed similiar problems along with a flickering screen.

Thanks for your help
Ken

 

[HRII_Pilot]

tried a new alternator over the weekend with no change. the problem is also getting worse. I now have a tach going from 2400 to 0 then back to 2400. I have officially ran out of ideas.

 

[jakej]

Ken -
FWIW I doesn't appear to be the Dynon (was replaced and still the same symptoms - I've never had a faulty unit) and your connections seem solid (crimp and soldered) however I'd thoroughly recheck your wiring ie make sure they ARE going to the correct sensors etc.

I found a customer who connected his Keep Alive (yellow wire - 12volts) to the fuel flow (yellow wire - 5 volts) which caused some issues  :  Not saying that you're at fault here   but we ALL need to make absolutely sure that we didn't 'introduce' a problem before we make a warranty claim especially as Dynon has replaced the unit and you STILL have similar problems.

Hope this helps and you find the cause  

regards,  Jake J