The air balance tube from the carbi float chamber to the airbox was a loose fit on the carbi nipple. So followed Ed's suggestion to apply a short piece of heat-shrink to the nipple to "fatten" it. Tube now fits nice and tightly.
Peter T instantly dianosed the negative amps message on the display - simply had to reverse the two small wires (!) on the main electric shunt to get psoitive amps on the display.
Fixing the 0 volts on the volt meter display is proving more difficult. Worked with Sheryl to check the continuity of all the leads heading from the regulator and battery - couldn't find any faults. Chatted to Peter T again then checked the connections from the sensors in the engine bay to the EMS remote head in the avionics bay - in particular, tracking and checking all the return wires (important in a composite airframe). It looks like the volt meter leads are not flowing correctly - no volts when when the positive input is connected to the negative return. So the next task is to unwrap the cable bundles and physically track the wires ...
Put 10 ltrs of fuel in the left tank to check the flow pressure issue. 2.0 psi using just the electric pump, and 700mm per minute (42 litres an hour) which is within spec. But when running, ie mechanical fuel pump working as well, still only getting 2.0 psi - which quickly drops to zero as soon as WOT is engaged .... Do more work there as well.
