Jim,

I use the VM probes with a VM indicator in our 320. They have worked
perfectly since day 1 with absoutely no variation from hydraulic pump, radio
transmissions, strobes or anything else. Our VM gauge reads all three tanks.
We also have the VM1000 system which has an independent fuel remaining
function (subtracts fuel used from a known starting quantity). The fuel
remaining function agrees within a gallon with the total of the three tank
quantity indications, which agrees with the fuel truck. The sight gauge on
the header agrees with the VM header quantity indication and the fuel level
float switches.

Maybe your EI probes aren't compatible with the VM stuff?  Good luck fixing
your indicating problem.

Bill
harrelson@erols.com
LNC2   O-320   VA42