ASE Engine performance

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?

• TECH A

• TECH B

• BOTH A and B

• NEITHER

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 normal condition

• late ignition valve or timing

• a burned exhaust valve

• a restricted exhaust

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

• Tech a

• Tech B

• Both A and B

• Neither

A vehicle emitting smoke from it's 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

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 a sensor contains a sensor. The PCM will detect low tank pressure, set a code and check engine light. who is correct?

• Tech A

• Tech B

• Both A and B

• Neither

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

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?

• Tech A

• Tech B

• Both A and B

• Neither

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. Who is correct?

• TECH A

• TECH B

• BOTH A AND B

• NEITHER

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?

• Resistance in the primary circuit
• An open between the coil and power source
• A leak in secondary insualation
• Resistance in the secondary circuit

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?

• Tech A
• Tech B
• Both
• Neither