I have a 1982-280sl-6 cyl--mercedes that has been in the garage foor two years.When I started it---it hesitates--.I have changed the fuel pump---fuel filter.The fuel pump "wines".When driving the car--it seems to hesitate at random.It seems that the fuel supply iis interupted.I also have tried to run injector cleaner in with the new gas(I drained the old gas).Sure coulld use some good suggestions.Thanks,Fred