By the way, I had a pressure guage plumbed into the cold start injector port, which I assume would be considered upper chamber pressure. As long as the fuel pump is running it read 5.5 bar and 2.5 bar after the pump is switched off. In a previous test it held 2.5 bar for over 72 hours. Injector lines #4 and #6 had slight fuel drips at fuel system pressure but stopped dripping at rest pressure.