tacho problem

[jaccoulin13]

Hello, i'm back.
After OAT, I have now a problem on my Tacho.
My engine is a 2.2 Jabiru, so I wired Alternator wire on pin 32, through a 1amp Fuse.
It looks me to have high idle rpm (1200rpm), and when putting trothle, my Dynon indication runs speedly from 2700 to 5000 or even 7000 rpm.
What can I do to stabilise my indicator?
What is setting for this engine (I set 5 for Puls/REV)?

Thank's a lot

 

[jakej]

Why did you use 5 ? :

What does the install amnual say re PPR for 4 cyl engines - when you get that correct you you maystill have rpm instability, but that requires another 'fix'

HTH

Jake J

 

[jakej]

Why did you use 5 ? :

What does the install amnual say re PPR for 4 cyl engines - when you get that correct you you maystill have rpm instability, but that requires another 'fix'

HTH

Jake J

 

[jaccoulin13]

Manual don't tell anything about number of puls / rev. Jabiru alternator supplies 2x5 phases. I finded so some samples of setting where setting was about 5.
I really have 2 problems.

 

[jakej]

IMO you should be using an 'even' number - try 4 PPR (6 works for the 3300 Jab).

HTH

Jake J

 

[jaccoulin13]

Hello, I thank my rpm rapport is finally right, but I still have problem of stability. Without changing trothle, my indication always moves, and some times, background becomes red, and indication runs higher.

Has anyone a solution?

 

[jakej]

Firstly I'd try connecting to the other alternator output wire and see how it goes. If that doesn't work you may have to add a resistor, experiment with different sizes (values), starting at say 30K Ohm.

HTH

Jake J

 

[jaccoulin13]

Hello, thank's for answering.
I tried on the other alternator wire, and after, I added some 10 K resistor, but with the same result. I'm thanking about a RC network, to suppress high frequency, but it looks me a little strange to have to do some thing like that. Am i the only one to get this kind of problem?

 

[jakej]

My experience has been with the J3300 engine and use 100K, 10K seems too low.

Jake J