Erratic Engine Temp

[knowlesbg]

Jabiru 3300
the only thing I currently have a problem with the EMS function is a high and erratic reading with oil temp
once the oil temp indicates a normal range in cruse it then after awhile proceed to increase and become wildly erratic.
Dynon on numerous occassions have addressed this in the forum as being a earthing problem and one answer that stood out was to change the temp sensor with an extra earthing wire to lead back to EMS ???
does dynon have a preferred sensor that will suit the JABIRU DIFFERENT FROM THE STANDARD

 

[jakej]

Generally these are rock solid but this one may be didfferent, I've done many installs on the Jabby's but had no issues with any of the sensors

You could remove the sensor, put it in a container of oil and extend the wire, then observe readings while heating it up. Then wriggle the wire at the sensor and EMS end and see what happens BTW - run a ground to the sensor as well while testing.

HTH

Jake J

 

[paulgy80]

I am having a nightmare with a 3300 install, have been trying to get my message across to Mark in customer service as we have spent now 3 solid days in total this time trying to sort out this issue, this has been going on now for a long while.

Erratic readings is an understatement, we have tried the D10 with the existing sensor (Jab supplied) on all sensor settings and throughout the temp range from 10c through to 110c, at the lower temps up to 30 the sensor and D10 works OK as it progresses up the temp range the disparity increases which when the sensor is at 100 the unit D10 reads 137. Went and got a new Jab sensor, same problem, this is after the unit has been sent back to Dynon and deemed OK. Next tried a Rotax sender, as they are reported to be better, same problem, at every sensor setting. Have checked the wiring and checked the normal Dynon reason of bad earth, we have no issues at all with that.

So as I in my limited knowledge way look at the problem and sitting in front of me is a speardsheet with readings up and down the temp scale with Ohm readings along side, they have been taken throughout the temps range at 5 and 10c intervals and they are all over the place,  I can only conclude there is a fundemental issue with the D10 working in conjunction with the VDO sensors for Jab and Rotax, otherwise why would I get the problem that I have?? :'(

If you have a resolution to this problem please please tell me as the customer is really well hacked off.

Paul

 

[dynonsupport]

Paul,

Since you're pretty involved with tech support directly (and that's the better resources for tricky problem solving than on here on the forum, where we'll actually refer stuff there once it gets to a certain point), and it looks like you've got an RMA, we'd like to keep that as the active channel for your issue.

The short answer is that as Jake indicates, that we don't believe that we have a fundamental or widespread problem with Jabiru engines and oil temperature readings.

 

[paulgy80]

Dear Dynon support

Yes we have been liasing with Mark H in Tech support and with our dealer in the UK who I have to say has gone above and beyond the call of duty. The dealer kindly sent me a loan D10 unit and we have tested it in the same installation, same poor results. We also at their recommendation ran additional checks on the wiring and found absolutely no fault.  Where this leaves us is with the knowledge that my customers D10 is the same as a new one, and that the sensor output to the D10 is creating the same sort of wacked out readings on both units. We also know to the very best of our knowledge that the wiring is sound with no additional Ohmage being present. The problem now we beleive lies in the D10 units convertion in the readings it is being reported by the sensor, the sensor is not your production, you say the Jab unit is to be used, we have tried 3 now one old Jab one brand spanking new Jab and a new Rotax 914 sensor, all reporting errounious readings on every sensor setting and at all temps other than ambient. We have now shipped the unit back to our dealer along with his loaner, this he is going to double check and then get to you.

In one of tech supports recent e mails Mark H sent an Ohm'age vs temp chart, we then ran tests but in degrees c not f and we sent to you guys a Spreadsheet of our findings nobody has not commented (don't know why) on the figures we had reported by the sensors tested, which I have to add were distinctly different to yours.

As I have said repeatedly all we want is a happy customer and a D10 that reports constistantly accurate readings.

Kind regards

Paul

 

[knowlesbg]

I forgot to mention the oil temp Sensor was replaced with the same thinking it was the problem but the fault remained.
Another issue that occurred was an erratic reading of one EGT (6). this I fixed (???) by separating this lead away from two other EGT leads supported at a common bracket. In fact while they were sharing the same bracket by just gently pulling on the problem EGT lead would stabilize the EMS readings (????). :-/

Bruce

 

[pbennett]

The EGT reading problem would be consistent with an intermittent short between the thermocouple wires at the support point. A tight cable tie could do this if you were unlucky.

Peter

 

[paulgy80]

Dear Dynon folk

Right you have had my unit back to you again, it now has more flying hours on it going to and from you than it has the the Jab J400 ! ! !

Now you have both unit and all the sensors, one 30 hour Jabiru sensor, a new Jabiru supplied sensor and a Rotax 912 sensor, this has been with you for a week plus and I have chased Dan from the UK dealers without success, please can I get sme feedback, hopefully some positive stuff to get this bird back in the air.

Kind regards

Paul