Hello friends here!
Hope everyone had a great Easter weekend
Three weeks later since the car first visited the new garage, I have been updated with the testing result: the high pressure fuel pump didn't pass the test (failed), but NO swarf found inside and the failure caused by an inner faulty valve. By replacing the valve, the pump works perfectly now.
And things that the garage will do in the following days are: 1) Replacing ALL four injector with new one and put the pump back. 2) Draining fuels out of the tank. 3) Flushing the fuel system. 4) Road testings.
Don't know if that's the correct solution...?