ASE Engine performance

Front

After performing a wet compression test, the pressure in each of the cylinders increased, but remained below specifications. Tech A says this is caused by incorrect valve timing. Tech B says this is caused by worn piston rings. Who is correct?

Back

Tech B

Front

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...

Back

a burned exhaust valve

Front

Who is correct regarding the effects of a stuck closed (EGR) exhaust gas recirculating valve and a stuck open EGR valve? Tech A says a stuck closed EGR valve will cause an engine to stumble or fall. Tech B says a stuck open EGR valve will cause detonation.

Back

Neither

Front

A vehicle emitting smoke from its tailpipe at idle. Which of the following is causing this condition? A leaking fuel injector, worn piston rings, a blown head gasket, leaking valve seals

Back

A leaking fuel injector

Front

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 will not illuminate the check engine light. Technician B says the tank contains a sensor. The PCM will detect low tank pressure, set a code and check engine light. Who is correct?

Back

Tech B

Front

The PCM uses all of these inputs to calculate air flow ratio and speed control EXCEPT... An engine coolant temperature sensor (ECT), An exhaust gas recirculation valve (EGR), An intake air temperature sensor (AIT), A throttle position sensor (TPS)

Back

An exhaust gas recirculation valve (EGR)

Front

Two techs are discussing a turbocharged engine. Tech A says the wastegate is a component used to control boost pressure. Tech B says when opened, the wastegate diverts exhaust gas from the turbine wheel. Who is correct?

Back

Both A and B

Front

Who is correct regarding the vacuum hose and fuel pressure: Tech A says when the vacuum hose is disconnected from the vacuum operated fuel pressure regulator, fuel pressure should increase. Tech B says a restricted fuel return line will cause low fuel rail pressure?

Back

Tech A

Front

A misfire is detected at the #3 cylinder of a COP ignition system. There is no power at the Bat+ terminal of the coil. What is the MOST likely cause of this condition?

Back

An open between the coil and power source

Front

The MAP sensor's vacuum hose is loose and cracking. Technician A says this sensor measures air mass to establish the fuel injector's base pulse width. Technician B says this sensor measures changes in intake manifold pressure. Who is correct?

Back

Technician B is correct.