ASVAB Automotive Information Practice Test 827208

Questions 5
Topics Actuators, Control Arms, Engine Block, Firing Order, Intake Stroke

Study Guide

Actuators

Actuators receive signals from the powertrain control module and carry out adjustments needed based on the data the PCM received from the sensors.

Control Arms

Control arms (upper and lower) connect a vehicle's suspension to the frame. The connection to the wheels is through ball joints which allow the control arms to turn and move up and down simultaneously. The frame connection uses bushings.

Engine Block

The engine (or cylinder) block is the large casing that contains the cylinders and many of the internal components of the engine.

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.

Intake Stroke

The four-stroke piston cycle of internal combustion engines starts with the piston at top of the cylinder head (top dead center or TDC) during the intake stroke. The piston moves downward in the cylinder creating a vacuum that pulls an air-fuel mix into the combustion chamber through the now open intake valve.