A8 Engine Performance Practice Test Questions with 100% Correct Answers

D. The PCV valve should rattle when shaken back and forth. When the thumb is placed over the end of the PCV valve with the engine idling, the plunger should snap back. A water manometer can be used to check the crankcase for vacuum at idle. No blowby test is performed on the PCV system. All of the following are tests performed on the PCV system EXCEPT: A. The rattle test B. The snap- back test C. Crankcase vacuum test D. Blowby test C. Faulty secondary ignition components are common causes of ignition module failure. Some modules require the use of dielectric grease to aid in dissipating heat. A fouled spark plug would cause an engine miss, but would not cause the ignition module to fail. Loose module mounting screws will cause the module to fail prematurely. Which of the following is the LEAST LIKELY cause of ignition module failure? A. An open spark plug wire B. No dielectric grease under the module C. A fouled spark plug D. Loose module mounting screws A. A partially restricted fuel return hose would cause the fuel pressure to be higher than it should. This would cause poor fuel economy without affecting drivability. A stuck open fuel regulator would lower fuel pressure, possibly causing a no-start, but would not cause a fuel economy complaint. A sequential fuel- injected vehicle has poor fuel economy, yet starts and runs fine. Technician A says the fuel return line may be partially restricted. Technician B says the fuel pressure regulator may be stuck open. Who is correct? A. Tech A B. Tech B C. Both technicians D. Neither technician A. The EGR system is used to lower combustion chamber temperature . If the EGR system does not operate, then the engine will operate too hot, causing spark knock and elevated oxides of nitrogen (NOx) reading. An inoperative EGR system will raise combustion chamber temperatures and cause the engine to run hotter. Technician A says if the passages in the exhaust gas recirculation (EGR) system get plugged up with carbon, then the engine could spark