EDM 900 Question

[thomas1142]

The manifold pressure reading on my EDM 900 fluctuates about an inch or so. Keeps bouncing up and down the entire flight, has been doing this since installation. It has the scrubber, or whatever it’s called, installed that was to take care of this issue. Any thoughts?

[ArtVandelay]

This is a common problem, you need to install a snubber...about a $10-$15 part.

 

https://mooneyspace.com/topic/12583-jpi-900-manifold-pressure-problem/

[thomas1142]

That’s what it’s called, thanks. Installed the snubber last annual, no luck.

[Marauder]

Just now, thomas1142 said:

That’s what it’s called, thanks. Installed the snubber last annual, no luck.

Make sure you don't have a tubing/fitting leak. A small pinhole leak will give you some strange readings.

[thomas1142]

1 hour ago, Marauder said:

Make sure you don't have a tubing/fitting leak

I’ll check that this weekend, thanks.

[carusoam]

Snubbers may have different calibrated hole sizes in them as well... too large, it won’t work right...

So... a part number check may be a good idea as well...

Best regards,

-a-

[thomas1142]

It’s been a while since last post, but the issue is finally resolved. After dealing with this for a year and trying all the suggestions I received, I finally gave up and called JPI. They had me send the the MP transducer and lo and behold it was defective. They sent me a new one, got it installed....no more fluctuations.

Main reason I followed up with this post is just to say that at times parts are just bad.....you do nothing wrong, installation was correct, your plane is responding correctly. 
 

Now to fix the freezing/locking up of the 7” G3X.

[carusoam]

Great follow-up Angelos!

Bob had similar challenge when he installed the JPI 930 in his M20E...

At the time, it seems as if JPI didn’t know what a snubber was, and why it was needed...

After Bob got them up to speed... they probably changed the sensor...    

Now there is a ton of wrong sensors in their inventory...  

unfortunately, Bob can’t be here to recant his experience...

Best regards,

-a-