trying to bring car back to life. been sitting in a garage for 7 yrs. replaced fuel tank,fuel pump,sending unit pressure reg,and fuel filter and still only get 30-35 psi at the rail. also car has developed a knock.the parts store code reader shows a bad cam sensor. what are the symptoms to look for. car will run sometimes and die other times. cant tell if this is fuel related or internal issue. any ideas?