EFIS issues

[Gary2418]

I have an RV7 with a GRT HS EFIS in it as well as an infinity grip.. In the last few weeks I notice I get wildly high readings on all my CHT and EGT,s when I push to talk on my stick. Once I stop transmitting the temps all drop back to normal. My thoughts are a ground issue somewhere but the setup has been working since 2011 and I have not changed anything. I only have the grip on the left side so I am unable to transmit with any other push to talk to see if the problem is in the stick itself. Any ideas.

I am also looking to upgrade my GRT HS EFIS to a GRT HX EFIS if anyone has one for sale.

Thank you,

Gary Abel
C-GGHG

[Mike S]

Originally Posted by Gary2418

I am also looking to upgrade my GRT HS EFIS to a GRT HX EFIS if anyone has one for sale.

Thank you,

Gary Abel
C-GGHG

Sure do.

8.4" HX --------- will PM you.

[BobTurner]

Check the com coax, especially the braid to ground plane connection.

[pilot2512]

What Bob said and also take antenna off and make sure it has a good bond to A/C ie no corrosion between ant and skin. Best if you can have someone do a VSWR test on the coax.

[ClayR_9A]

Are you using the GRT EIS for your sensors? It then transmits the readings for display in the EFIS.

I have that setup, and when my Princeton fuel senders went bad and caused a short, all the OTHER sensor values went crazy. For example, my voltage reading showed 24v even though it was 12v. CHTs and EGTs also showed values out of range.

The correlation with transmitting only is interesting, but my guess is some kind of short somewhere-- probably involving the radio/antenna or PTT.