RV-12iS Low Voltage to Fuel Pumps

[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.

 

[unladenswallow]

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?

Are the fuel pump voltage and RPM low right from before you start the engine, or only after generator swap has occurred? If right from the start then I would suspect poor connections to the new HIC module. Preferably, crimp ferrules onto the wire ends before you insert them into the connector block, as shown in the photo in the SB. Check the wiring as described in the SB, and check that the terminal block connector is fully engaged and the two screws secure.

If the problem only occurs after generator swap then I would suspect the generator A regulator and associated wiring including the generator A ground connections.