EFIS starting to fail... need to replace

[ldmill]

Guys,
I've got an older MGL Stratomaster Ultra Horizon EFIS that appears to be going belly up(10+ yrs old). It started several months ago with the altitude readout becoming erratic occasionally - it would suddenly offset by anywhere from 1000 to 5000+ feet. Today, the fuel flow rate started wandering around, at times indicating 0 gph flow during extended cruise periods. I've got a Bing installed, so the float bowl can buffer this some - but not 5-10 minutes at 2800 rpm... A little pucker factor confirming it was not fuel pump (stayed over airfield), but I feel comfortable about it at this point. It may be the fuel flow transducer - but I'm slightly more suspect of the EFIS itself right now. All wiring & pneumatic tubing appears to be okay. Airspeed indicator is still working correctly.

So, the question is - does anybody have an Ultra Horizon or even the somewhat newer Enigma (uses same RDAC) they are no longer using and would part ways with? I would prefer to not install a whole brand new EFIS system at this point with everything involved in doing so...

Lorin Miller
N81YX 280 hours and going strong

[achesos]

Hmm. Multiple failures could certainly be plausibly caused by the Ultra, but with a variety of observed discrepancies, I'd wonder if this isn't the standard trailer-light phenomenon usually caused by poor grounding. Or not? Something to consider / investigate. Just spit-ballin'...