26.

Answer A is wrong. Both technicians are correct.

Answer B is wrong. Both technicians are correct.

Answer C is correct. A stuck closed EGR valve will cause ping (detonation) while a stuck open valve will cause an engine to stumble and stall.

Answer D is wrong. Both technicians are correct.

Return    Learn more about detonation and preignition.

27.

Answer A is wrong. Technician B is correct.

Answer B is correct. Clean the pistons in a cold tank and clean the grooves with a ring groove cleaner before measuring.

Answer C is wrong. Technician B is correct.

Answer D is wrong. Technician B is correct.

Return    Learn more about piston ring installation.

28.

Answer A is wrong. Both technicians are correct.

Answer B is wrong. Both technicians are correct.

Answer C is correct. Both restricted fuel injectors and leaking secondary wires will reduce the cylinders contribution. Anything that would have an effect on the cylinders power. It could be mechanical like a faulty valve, possibly the ignition, or the fuel mixture affecting this cylinders power output.

Answer D is wrong. Both technicians are correct.

Return    Learn more about cylinder balance testing.

29.

Answer A is wrong. The wastegate is controlled by a valve and releases excess pressure back to the exhaust stream. This device is used to control intake manifold pressure.

Answer B is wrong. They are both right. When the gate opens exhaust by-passes the turbine wheel reducing intake manifold pressure.

Answer C is correct. Both technicians are correct.

Answer D is wrong. Both technicians are correct.

Return    Learn more about turbochargers.

30.

Answer A is wrong.

Answer B is wrong.

Answer C is wrong.

Answer D is correct. Excessive fuel is burning in the catalytic converter causing the sulfur odor.

Return    Learn more about the causes and effects of a rich fuel mixture.