ASE A8 Engine Performance Practice Test
1. After performing a wet compression test, the pressure in each of the cylinders increased, but remained below specifications. Technician A says this is caused by incorrect valve timing. Technician B says this is caused by worn piston rings. Who is correct?
- A. Technician A
- B. Technician B
- C. Both A and B
- D. Neither A or B
2. A vacuum gauge is connected to a port on the intake manifold of an engine with poor performance. The needle on the gauge fluctuates between 15 "hg and 20 "hg vacuum at idle. This vacuum gauge reading indicates:
- A. A normal condition.
- B. Late ignition or valve timing.
- C. A burned exhaust valve.
- D. A restricted exhaust.
3. Technician A says a stuck closed (EGR) exhaust gas recirculating valve will cause an engine to stumble or stall. Technician B says a stuck open EGR valve will cause detonation. Who is correct?
- A. Technician A
- B. Technician B
- C. Both A and B
- D. Neither A or B
4. A vehicle is emitting black smoke from its tailpipe at idle. Which of the following is causing this condition?
- A. A leaking fuel injector.
- B. Worn piston rings.
- C. A blown head gasket.
- D. Leaking valve seals.
5. A vehicle with an enhanced EVAP system is scanned and a code indicating a small evaporative emissions leak is detected. A loose or cracked gas cap is suspected. Technician A says the cap contains a vacuum and pressure relief valve, a small crack in the cap will not illuminate the check engine light. Technician B says the tank contains a sensor. The PCM will sense low tank pressure, set a code and illuminate the check engine light. Who is correct?
- A. Technician A
- B. Technician B
- C. Both A and B
- D. Neither A or B
