20023 Already Passed
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. ✔✔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. ✔✔A
What most likely is the cause if the compression goes up during a wet compression test?
A, burnt valve.
B, worn piston ring. ✔✔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. ✔✔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. ✔✔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 ✔✔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. Technician B says that an intermittent
open in the pickup coil leads could be the cause. Who is right?
A. Technician A only
B. Technician B only
C. Both A and b
D. Neither A or B ✔✔B. If a vacuum advance mechanism were stuck, the problem would not
change if the vacuum hose is connected or disconnected. When the vacuum changes to the
vacuum advance mechanism and the distributor plate moves, this may move the wires to the
pick-up causing a short or open which would cause the pick-up signal to be lost momentarily.
6. Technician A says that spark advance on and engine can be tested by listening to the way the
engine sounds at higher rpms. Technician B says that spark advance on an engine can be tested
with a timing light that incorporates an ignition advance meter. Who is right.
A. Technician A only
B. Technician B only
C. Both A and B