[Special Delivery]

RV-12iS - Low voltage to fuel pumps...
Independently, fuel pumps #1 & 2 run at reduced rpm and pressure.
All other electrical devices operate normally; starter, lights, radios, etc.
ECU emergency power switch ON (direct battery) helps some.
Also experiencing ECU ‘ignition’ related fault codes... suspect may be caused by whatever is causing low voltage to fuel pumps.
*Latest changes to electrical system (prox 50 hrs ago): Installed new HIC module AV-60009-2 and Ignition Module Firmware Update ES-60016-7.3

Verified battery condition 100%
Verified ground connections; battery to case, case to airframe, Rotax fuse box/regulators A&B, etc.
All connections on HIC and Rotax fuse box verified tight and/or re-seated.
All connections on back of fuse/switch panel verified tight and/or re-seated.

I'm at a loss as to cause... any help out there?

 

[Bob Y]

Have you tried jumping 12 V directly to the pumps? I know it won't be easy, but will help confirm if it’s the pumps. And when you say “low voltage”, is it because you have measured the voltage at the pumps? If it’s low pressure but not low voltage, I would suspect something in the fuel line, like clogged filter or pressure regulator. You could disconnect the fuel line at the engine fuel rail to see what kind of flow you get ahead of the regulator. One of those might help better identify the problem area.