Originally Posted by
Maxmill59
Yes both indicators have fluctuations.
Based on what you’ve posted, my guess its a supply/return problem with the airframe fuel system. Since you’ve changed the engine pump and the unmetered fuel is still fluctuating tells me you have more a supply obstruction, cracked fitting, loose connection, collapsed line, etc. restricting the engine pump pick up fuel supply. And given you can duplicate the problem on the ground, if it were me, I would connect a test fuel supply/return system at the engine driven fuel pump and run it to see if it makes a difference before I'd throw any more parts at it.