ASE A8 Engine Performance Quiz

1. Technician A says the PCM will advance ignition timing when it receives a voltage signal from the knock sensor. Technician B says this sensor sends an AC signal to the PCM when it detects ping or spark knock. Who is correct?
2. A misfire is detected at the #3 cylinder of a COP ignition system. There is no power at the Bat+ terminal of the coil. Which of the following is the MOST likely cause of this condition?
3. An enhanced EVAP system has a code indicating a gross leak detected. Which of the following is the MOST likely the cause of this condition?
4. A catalytic converter is damaged from heat. Technician A says this heat damage is caused by cylinder misfiring. Technician B says this heat damage is caused by low fuel pressure. Who is correct?
5. A vehicle has a fuel trim of -5 at idle and -25 at cruise. The vehicle has a steady oxygen sensor reading of 800Mv. When a vacuum hose is disconnected from the intake manifold there is no change in the oxygen sensor's output. This condition is caused by:
6. A vehicle cranks but will not start. As the technician turns the ignition key the security light continues to flash slowly. Which of these is MOST likely the cause of this condition?
7. A vehicle is backfiring and has a lack of power. Technician A says it may be the catalytic converter and a back pressure test should be performed. Technician B says a vacuum gauge can be used to diagnose a restriction in the exhaust system. Who is correct?
8. Two technicians are discussing code P0301. Technician A says the P in the code stands for powertrain. Technician B says the 0 in the code means it is manufacturer specific. Who is correct?
9. Technician A says when the vacuum hose is disconnected from a vacuum operated fuel pressure regulator, the fuel pressure should increase. Technician B says a restricted fuel return line will cause low fuel rail pressure. Who is correct?
10. An EFI engine stalls and then starts back up. Sometimes it takes several tries to start. Technician A says a loose connection at the crankshaft position sensor would result in this condition. Technician B says an open at the crankshaft position sensor would result in this condition. Who is correct?
11. An EGR valve vacuum solenoid has 18 "hg. as its vacuum source. The resistance checks out OK. Vacuum pressure is manually applied to the EGR valve with a pump and a slight stumble is noticed. There is little drop in rpm. This is caused by:
12. A cylinder power balance test is being performed on a vehicle with sequential fuel injection. Two adjacent cylinders are under performing. Technician A says this could be caused by a restriction in the fuel injectors. Technician B says this could be caused by leaking secondary insulation. Who is correct?
13. A COP ignition system has no spark at any of the coils. Which of these is MOST likely the cause?
14. Technician A says the MAF sensor is located on the intake manifold, and informs the PCM of intake manifold pressure. Technician B says the MAF sensor senses air volume in the air tube. It's signal indicates engine load to the PCM. Who is correct?
15. Technician A says a throttle position sensor is a potentiometer that indicates throttle angle. Technician B says a throttle position sensor can be tested for resistance with an ohmmeter. Who is correct?
16. 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 camshaft timing. Technician B says this is caused by worn piston rings. Who is correct?
17. 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:
18. 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?
19. A vehicle is emitting black smoke from its tailpipe at idle. Which of the following is causing this condition?
20. An engine suffers from a lack of power during acceleration. A vacuum test is being performed. At 2500 rpm the vacuum gauge needle drops slowly and then reads 10 "hg. Which of the following is causing these vacuum test results?
Please select an answer