ASE-A8 Engine performance with Complete Solutions

If the compression is 5 psi and the oem spec is 140 psi, what most likely is the cause? A, worn piston ring. B, burnt valve. - ANSWER-Both A and B What most likely is the cause if the compression doesn't go up during a wet compression test? A, burnt valve. B, worn piston ring. - ANSWER-A What most likely is the cause if the compression goes up during a wet compression test? A, burnt valve. B, worn piston ring. - ANSWER-B 2. Blue smoke is coming from the exhaust pipe of a vehicle, what most likely is the cause? A, worn piston ring. B, bad head gasket. - ANSWER-A 3. A vacuum guage is connected to the intake manifold of an engine and the engine is run at 2000 rpm. During the test, the pointer on the guage fluctuates rapidly between readings of 10 and 20 inches of vacuum. These test results point to: A, a leaking intake manifold. B, worn piston rings. C, worn valve guides. D, a week or broken valve spring. - ANSWER-D, a weak or broken valve spring would cause a vacuum guage to fluctuate or jump from high to low readings. 4. Engine detonation (knock) could be caused by any of the following Except: A. a lean air/fuel mixture B. retarded ignition timing C. excess carbon in the the combustion chambers D. a stuck-closed EGR valve - ANSWER-B. Advanced ignition timing will cause a knock, but retarded timing will not. 5. A vehicle with electronic ignition hesitates and stumbles during acceleration. The problem goes away when the vacuum advance hose is disconnected and plugged. Technician A says that a stuck vacuum advance mechanism could be the cause.