It is not a turbo, just a standard b230f, and now the slight vibration actually happens around 1300 - 1400 rpm, while in neutral or park. Suprisingly doesn't occur when in first gear around 1400rpm, although there is still a slight hesitation in accelarating which is hardly noticeable. So the problem only happens when stationery. What am I too look for??? and whereabouts is the fuel pressure regulator (what does it look like?)

Thanks in advance?

Steven