A1 ASE Test questions with correct answers

If an engine experiences a sharp, metallic rapping noise only when it is idling, the trouble could be worn: `Main bearings `Piston pins `connecting rod bearings `piston skirts - Answer Piston pins On a port fuel-injected engine, the cause of excessive black smoke in the exhaust could be: `low fuel pressure `an intake manifold vacuum leak `high oxygen sensor voltage `high fuel pressure - Answer High fuel pressure During a cylinder power balance test on a four-cylinder port fuel-injected engine, one cylinder has a 75-rpm drop and the other cylinders have a 125-rpm drop. Technician A says that the cylinder with a 75-rpm drop may have a burned exhaust valve. Technician B says that the cylinder with the 75-rpm drop may have a bad fuel injector. Who is correct? A only B only Both A and B Neither A nor B - Answer Both A and B