ASE A8 Engine Performance Practice Test
21. Technician A says a MAP sensor measures air mass in the air intake tube to establish the fuel injector's base pulse width. Technician B says a MAP sensor measures changes in intake manifold pressure. Who is correct?
- A. Technician A
- B. Technician B
- C. Both A and B
- D. Neither A or B
22. There is a misfire at the #3 cylinder of a COP ignition system. There is no power at the Bat+ terminal of the coil's plug. Which of the following is causing this condition?
- A. Resistance in the primary circuit.
- B. Resistance in the secondary circuit.
- C. A leak in the secondary insulation.
- D. An open between the coil and it's power source.
23. The OBD II Enhanced Evaporative Emissions monitor has illuminated the check engine light and set fault code P0457 indicating that a gross leak has been detected. Which of the following is the MOST likely cause of this leak?
- A. A crimp in the vent hose.
- B. A saturated canister.
- C. A stuck closed purge valve.
- D. A loose fuel filler cap.
24. A vehicle with a four cylinder EFI engine has poor acceleration. Scan tool data indicates the engine has a LTFT of -19 % at idle indicating a rich air fuel ratio. Technician A says too much fuel in the air fuel mixture will damage the substrate of the catalytic converter. Technician B says a LTFT of -19 % indicates the PCM is adding fuel to the air fuel ratio. Who is correct?
- A. Technician A
- B. Technician B
- C. Both A and B
- D. Neither A or B
25. A vehicle has a fuel trim of -5 % at idle and -25 % at cruise. Scan tool data indicates a steady oxygen sensor output voltage of 800Mv. When a vacuum hose is disconnected from the intake manifold, there is no change in the oxygen sensor's voltage. This condition is caused by:
- A. An intake manifold leak.
- B. A faulty throttle position sensor.
- C. A faulty oxygen sensor.
- D. A kink in the fuel return line.