Check that your fuel flow transducer has not been installed backwards. It is posible that no staining will be observed because the pressure is great enough to pull air into the system but not let fuel escape. Make sure the unit is properly programmed for twin application. If programming is not the cause, make sure the transducer power, signal and ground lines are correctly wired. Remember that in some of the system left and right power is shared and left and right grounds are shared.
Transducers are individual, hand made items.
When they go through the calibration procedure, whatever K-Factor they flow out at is what they will be, there is no changing this number. The indicator in the cockpit is the system which can be changed to any k-factor setting. 88888 will flash across the screen, release the button. Compare this number with the red calibration tag on the side of the 6605XX transducer. They should be the same.