I have a problem. My car won't start when it's hot. It loses pressure (doesn't hold 3 bar pressure for half a hour). Apparently the fuel evaporates in the line and the car won't start until engine has cooled sufficiently for fuel to travel through. Have changed one way valve in fuel pump, cleaned and checked metering head, checked all injectors and seals. Have changed oxygen sensors. The only thing I haven't checked is a valve at the back of the engine (looking at the engine, there's a valve on the engine wall at the rear left - I don't know what this is and it's the only thing I haven't checked). Could this be the problem? Any other ideas? Darrin Jacobs