Chevrolet Antique Cars Motor Fails to Start Troubleshoot Guide
Chevrolet Antique Cars Motor Fails to Start Troubleshoot Guide How the Motor Operates, Motor Fails to Start and Water in Gasoline System of Old Chevy.
How the Motor Operates
The Chevrolet motor is the overhead poppet valve type. All models have four cylinders on which the firing sequence is 1-2-4-3.
All Chevrolet Motors are “Four Cycle,” which means there are four complete strokes of the piston or two complete revolutions of the flywheel to complete one firing sequence.
- As the piston starts downward in the first stroke of the cycle the intake valve is opened. The motion of the piston creates a vacuum in the cylinder and draws a charge of gas from the carburetor through the valve opening.
- When the piston reaches the bottom of its stroke and starts upward on the second stroke of the cycle, the intake valve closes and the piston compresses the gas that is drawn in to the space at the top of the cylinder.
- As the piston reaches the end of its upward stroke the compressed gas is ignited by an electric spark which occurs at the points of the spark plug and the resulting explosion or expansion pushes the piston downward, turning the crank shaft on the third cycle or working stroke.
- On the upward stroke of the piston, the exhaust valve is opened and the piston forces the remaining burned gas out through the exhaust pipe leaving the cylinder empty and ready for the beginning of a new cycle.
Motor Fails to Start
If for any reason the motor does not start immediately under its own power, remove your foot from the starting button at once. One of the following things may be causing the trouble:
Ignition switch may not be turned on.
The storage battery may be partially discharged and when the starting motor is in operation, not enough electric current is flowing to the coil to produce a spark sufficient to ignite the gas.
The coil may be burned out.
The contact points in the distributor may not be opening or the points may be burned so badly as to remain open.
The primary wire from coil to distributor, coil to switch or to battery, may be loose or broken, making poor contact.
Spark plug points fouled with oil or carbon.
Secondary wire from coil to distributor cover disconnected at coil. Gasoline supply exhausted.
Filter screen in carburetor or vacuum tank may be clogged with sediment so gasoline cannot enter float chamber.
Gasoline line may be clogged with dirt or if it is cold weather an accumulation of water in the line may have frozen.
The carburetor choke rod may not be pulled out far enough, providing the motor is cold, to make the mixture rich enough to ignite, or the choke valve may have been closed too tight, causing the mixture to be so rich with gasoline that it will not ignite.
Water in Gasoline System
If there is water in the gasoline it will not mix, but, being heavier than gasoline, will find its way to the bottom or lowest point in the system, which is at the carburetor. In cold weather it may freeze. By pouring hot water or applying hot cloths to the supply pipe and carburetor this can be loosened up. If poured on, be careful that none enters the carburetor.
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Source – This article courtesy should goes to : Chevrolet Repair Guide of 1923 by Chevrolet Motor Company.