ASVAB Automotive Information Practice Test 958234

Questions 5
Topics Combustion Chamber, Firing Order, Powertrain Control Module, Springs, Water Pump

Study Guide

Combustion Chamber

The combustion chamber is located in the cylinder head and contains the combustion of the air-fuel mixture. This mixture is delivered by an intake valve and the waste gases from combustion are removed from the combustion chamber by the exhaust valve.

Firing Order

The stroke cycle of an engine is governed by the crankshaft which serves to regulate the firing order of the cylinders. All cylinders are not on the same stroke at the same time and correct firing order is important to balance engine operation and minimize vibrations. A common firing order for four-cylinder engines is 1-3-4-2 which indicates that cylinders 1 and 3 fire (power stroke)together and cylinders 4 and 2 fire together.

Powertrain Control Module

The main computer or powertrain control module (PCM) uses pre-programmed software to analyze the input received from sensors and produce output signals to adjust vehicle performance and operation. (Engine control unit (ECU) is another name for the PCM.)

Springs

Suspension springs are made with wide gap coils of rigid steel cable and both hold the vehicle chassis up off the ground and absorb energy from wheel movement making for a smoother ride.

Water Pump

The water pump is driven by a belt connected to the crankshaft and ensures that coolant moves through the engine and radiator.