I had a real problem with starting my R300 from cold. In fact, it would not fire at all when cranking, but would start and run immediately, if I squirted fuel into each throttle body. This turned out to be a bad earth on the ECU, plus cleaning all the major earth connections dramatically improved the battery voltage dip on cranking, which helped the ECU fire the injectors. It may not be your issue, but cleaning all the main earths will hopefully help. Piers