DIY engine monitoring system

[CaptTom]

Thank you for responding. Do you know from your research anything about products like Noland (RS11), Actisense (ECM-1), maretron if these device are any good. Some claim to read voltage/ resistance from existing sensors to be displayed on a gps screen such as Garmin units. Also, some read engine computers (MEFI 1) and translate it to Nema2000.

Do you know if these work or know of any direction to look in?
Thanks again

I use a Noland RS11. It works great to monitor some values off my two old non-computerized Perkins diesels. The data goes right into the NMEA 2000 network and I can display it on a number of different screens, including a Garmin MFD.