The Fuel and Exhaust Systems

1. The fuel system starts with the fuel tank. As long as this tank isn’t completely filled with gasoline, there’s a certain amount of air in the tank, and the moisture in this air can condense into water. In cold weather this water can freeze into pellets of ice which cut off the fuel supply through
the fuel line and stall the engine. The best way to avoid this problem is to keep your tank filled as much as possible, thus reducing the amount of air in your tank. A warning sign of icing is frost on the inside of your gas cap. To protect against gas line icing, pour a can of fuel system de-icer in the tank once a month during the winter months. However, if the gas line is frozen, leave the car in a heated garage for several hours, since the additive will not freeze the gas line.

2. The automatic choke, as you know, provides the carburetor with a very rich mixture when the engine is starting from cold. It’s a good tip to have the mechanic check the automatic choke occasionally for proper operation. When it’s not operating efficiently, the automatic choke can
cause lots of grief in cold weather starting, as well as wasting gasoline.

3. Another small but vital element in your fuel system is the fuel filter; make very sure that it’s replaced at the recommended intervals. A clogged fuel filter will restrict the flow of gasoline just when you most need it.

4. The filter in the air cleaner must be replaced or cleaned at the recommended intervals. If this job is neglected, the carburetor and engine may be damaged, and your engine’s performance will suffer. To be on the safe side if you drive on dusty roads change the filter twice as often.

5. The exhaust system quietens the engine and gets rid of burned gases, one of which, carbon monoxide, is deadly. Have the system inspected at least twice a year, and be on the alert constantly for any unusual noise or smell that might point to exhaust trouble. If you think there may be damage, drive to a service station for inspection with your windows open. Never switch your engine off, then on again while driving: you just might explode your muffler. Never drive with a damaged or broken exhaust support bracket; you could be risking not only leaks but a fire. And, as everyone should realize, never run your engine inside a closed garage.

Spark Plugs

6. How to check the spark plugs. Many mechanics use the spark plug as a simple diagnostic tool. The normal color for the spark end of the plug is light tan or gray. If you find the spark end is black, contains any goo, or appears to be damaged, it may indicate you need a complete tune up or that you have a problem that includes more than just the spark plugs (though such plugs will have to be replaced too).

7. How to make the spark plugs last. A set of spark plugs can last as long as 10,000 to 12,000 miles on cars with conventional ignition systems and 15,000 to 30,000 miles on cars with electronic ignition. These figures are for optimum driving conditions. A new set of spark plugs once a year is a good investment to ensure fast winter starting. Changing spark plugs is easy, although it is not a complete tune up. For less than ten dollars you can change the plugs in most cars. The owner’s manual tells you exactly what type of plugs your car needs. All you need is a spark plug wrench, which is available at most department stores.

8. An important factor in the proper operation of your spark plugs is the distance between the two electrodes. This is called the ‘gap’, and different engines require different distances. The proper gap distance can be found in your owner’s manual, and it is measured by a special set of
metal blades, each a different thickness.

9. The spark plug wires should be clean. Gently wipe them with a rag. Don’t yank on them - you can crack the carbon core that carries the electrical current. Clean off corrosion around the terminals of other wires and tighten the connections.