First start and CHT/EGT issue

[Gripdana]

Today I started my Aerovee for the first time. All went well. It started right up. I need to finish tuning the aeroinjector so that it will Idle and work on the timing which is very close. The big issue I had was with the CHt and EGT's. I am using an Extreme EFIS and MGL RDAC. The CHTs' were showing hot and the EGT's had no reading. I only ran the engine for less than a minute. Anyone have any idea what I can do?

[Rynoth]

I'm about a month from completing my probe installations and am therefore studying installation methods. I'll also be using an MGL RDAC for my readings. My first question is, how are your temperature probes grounded? Was any sealant used when the EGT/CHT probes were placed that might interfere with their ground? How is the the engine block grounded to the battery? How are the probes grounded to the engine block/battery? How is the RDAC grounded to the engine block/probes?

[Gripdana]

The battery, engine block and starter are all connected together at the ground block with #2 wire. I did not use any sealant on the EGT's both the + and the ground are connected to the RDAC as shown in the RDAC instructions. The only thing I can think could be wrong is the assignment of the probes when set I up the EFIS. I could have the CHT for GET and visa versa. The RDAC ground goes directly to the ground block.

[Fastcapy]

-----

[Gripdana]

Thank you.That would be great. I was in a hurry to get home today and did not double check how I hooked up everything. I have 4 EGT's and 4 CHT's. I'll go to the hanger tomorrow night after work and take some photos of the RDAC and the set up menus on the EFIS.

[Gripdana]

I was just looking at the RDAC documentation. I think I may have + and - reversed. I have J type CHT probes and the - is red and + is white. I am sure I have them reversed. I'll check this tomorrow night.

[ScottM-Sonex1629]

Dana,

When I read my RDAC wiring manual it states very clearly the RDAC should be grounded directly to the ENGINE, and not the common battery ground.

As others stated make sure all the wires are landed correctly and the setup in the Xtreme is with the correct values.

Congrats on the first startup! That's awesome!

[Gripdana]

I did see that when I installed. I figured it was ok to go #2 wire from the engine block to the ground block and #2 from the battery to the ground block. I have sent an email to MGL and am awaiting a reply. When I go back to the hanger I will change the ground to directly to the block or I may jump from the block to the same spade connector on the ground block (daisy chain).

[saddler]

Your ground setup should work, that's how mine is set up and it works just fine. I confirmed this with Matt at MGL when I was chasing my issues. I'll bet you have the polarity of the thermocouples reversed. I did it too :lol: Red is -