EMS reading oddities

[RV6-KPTW]

Hey guys,

I am noticing an increasing number of instrumentation oddities.  A couple of things:
- a while back, I saw that my CHTs were reading low - seem normal in climb, up to 350F but 270F in cruise, 250F in long descents even with power on.  This has been a constant for about 2 or 3 years
- several months back amps went very negative and then rapidly changed but usually stayed negative - voltage stayed constant so I thought...hmmmm....  instrument error.
- yesterday, Oil temp was in the normal range (180-190) then gradually crept down to 150 with same power setting.  Now I think, hmmm... more than 1 instrument?? Maybe the EMS unit?

What do you all think?  A series of connections going bad, the coincidence of a series of sensors going bad, the EMS doing something interesting, or d). none of the above?

Am I seeing a trend here?  Maybe.  But of what?

Thanks for listening.

Dennis

 

[Raymo]

Make sure the EMS has a good ground to the engine.

 

[jakej]

Where is the ems mounted ?
Is it an RV with tip up canopy ?

 

[RV6-KPTW]

I will check the grounding.  This is a slider RV6 and the panel is about 4 or 5 years old. The EMS is mounted behind the panel.  Not a lot of room and it might be pretty hot back there - we are seeing over 30C temps here in our summer.  Makes some of the temps I noted even odder.

I am finishing up an RV14 so have not been spending as much time as I’d like with the 6.  Maybe she is acting out?

 

[jakej]

As Ray says, check your grounds for the EMS thoroughly.

Are you using a forest of tabs ? & , if yes, the push on terminals from the same source ? Other cheap low quality terminals can cause grief. I always make sure that I use the grounds out of the ems ( sometimes splitting them if necessary) & a ground almost directly to the battery. It actually is connected directly to the ground strap bolt on the firewall - never had any issues doing it that way