Discrepancies between fuel consumed after G3X Touch restarted.

[BoyRacer]

Have been recording fuel consumed on engine shutdown on my G3X Touch (GDU460 Running V9.31) and then carefully measuring actual fuel top ups so I can fine tune the K-factor on the red cube FT-60 flow transducer (Use the adjust fuel used method over the manual adjustment of k-factor in config mode.)

Have noticed after re-fuelling and restarting the G3X the amount it had previously recorded for fuel consumed has slightly changed before resetting or adjusting it?

Will attempt to get some screen shots on next shutdown/refuel however has anyone else noticed this behaviour on a G3X please?

 

[PilotjohnS]

Just me

I have been fighting my Kfactor optimization for 80 hours. I am within 5% but cant get a y closer.

All I can think of is my firewall forward plumbing is not good enough and is causing turbulence

This my not be your problem but is similar in that the kfactor ever seems perfect.

 

[hgerhardt]

I've never noticed the pre/post consumed fuel discrepancy, but I'll make it a point to check that someday.

With the K-factor fine-tuning, I got a much more accurate factor by running at least 5 or 6 tanks' worth of fuel and keeping track of how much fuel added in total divided by what the G3X said I used. With this method, you don't have to completely fill the tanks with each fill-up either. Start with full tanks and reset the G3X, and then keep a record of the running total of added fuel, and when you want to calculate the final total, then fill the tanks completely again.

So basically what I did was calculate the K-factor over ~180 gallons which included 25+ engine starts.

My reported fuel usage at each fill-up is within a quart or so of actual usage, which to me is amazingly close.

 

[Ironflight]

To the original question deltas between shutdown and startup, I also log fuel quantities on my kneeboard at shutdown and startup (I’m an engineer….), and have occasionally seen a 0.1 gallon difference. I always figured it was a figurative coin flip/rounding thing…..

Never seen more than that, so if it is for you, it’s curious!