I have read all sorts on this tread.
The valve was used because it provided automatic control over the fuel flow to the engine. Back in the day when starting manually many people had problems in starting engines and it was not uncommon to see fuselages roasted. This was normally due to opening the manual fuel valve during the start having forgotten to open it at the start. Also the starter motor needs a separate power supply and the battery may not have been freshly charged. Also people found it difficult to juggle the externally applied igniter for the glow plug, the gas supply, and electric power for the starter. By all means switch the ecu back to manual mode (the Xicoy unit can be toggled in the menu structure when the start mode is displayed). Do not come back and moan though if you toast the fuselage.
The little valve only opens when power is applied. No power and it stays shut with the spring inside. If fuel is filtered then it is very rare for valves to get stuck. on one of my planes last weekend I managed to block the vent with it on the stand and the first of the 2 tanks was pressurised, it quickly had bent sides rather than flat ones and the bung started to spray fuel out of it. I was concerned that the valve would have leaked fuel but none went through it and the start was normal. In normal use the valve should not leak fuel past it.
How many of you have ever seen a runaway pump caused by an ecu?
John