Hey guys, my 2008 350 CGI shakes very much on idle after cold start. Also, if not restarted after warming up it might stutter big time when accelerating, when driving at higher speeds etc. It shakes as if it wants to turn off when releasing throttle. A few days ago, after starting the car i just revved it up a little, say like 2000 rpm, and after releasing the gas pedal it dies. Started again, every time i do this process, after releasing the gas pedal it shakes, almost turning off. Fuel consumption is bad and the car just doesn't perform right. Went to the mechanic some time ago, and he told me ALL cylinders have misfire codes, and that he suspects either high pressure fuel pump or tank fuel pump gone bad. However, he recommended I try to thrash drive it a couple of times to see if it 'clears up'. Didn't help. Now all service shops are closed due to coronavirus, so thought I'd ask here if anyone had similar issues. Also, after warming up, driving some time, say 10 minutes, and restarting the engine it runs fine. Performance is up, fuel consumption is down and there is no shaking or stuttering anymore. But I do need to restart the car to achieve this. Any help is appreciated.