Prior to the mid 1980's most cars were fueled through a carburation system. Now most vehicles have fuel injection systems. This is a more efficient way to deliver fuel to the engine. Fuel injectors have less problems and adjustments than carburators. However, there is still maintenance that needs to be done. These generally last a long time, but a frequent problem is clogging. This can be remedied by using an injector cleaning recommended by the owner's manual. The majority of the time, however, a professional flush is necessary to clean the injectors. In addition, it will also improve fuel economy, increase horsepower, remove gum and varnish, and lubricate upper cylinders. Replacing the fuel filter every 25,000 miles will also help keep the fuel injection system clean.

See our Video on Fuel Systems

 

How Can I Improve Gas Mileage?

By Jim Prahl

That question is perhaps the most frequently asked by both listeners of the Auto Doctor program and by my customers.

The answer is to make sure that the vehicle in question is maintained and performing properly. If the vehicle is serviced at regular intervals (15, 30, 45.000 miles, etc.) then the vehicle is usually going to get good mileage.

Computers on automobiles today make hundreds of adjustments per second based on input from certain sensors. If your vehicle has a plugged fuel filter, the oxygen sensor senses a deduction of fuel system which causes a reduction of not only gas mileage, but also robs your vehicle of power (sluggishness).

The same is true of spark plugs or ignition cables that are not replaced at proper intervals because the computer is aware of the reduction of spark and making necessary adjustments to compensate for improper tuning. Since the computer is compensating for improper maintenance, people are unaware there's a problem until the problem gets so bad that eventually the computer can't do anymore. By then, other damage can occur (catalytic converter failure, ignition module or igniter failures, etc.) and that gets costly.

Tune your vehicle every 25,000 to 30,000 miles (vehicles designed for platinum plugs can go much longer), replace ignition cables, distributor caps, distributor rotors (if applicable) every 60,000 miles. Replace the fuel filter every 15,000 miles and most of all realize that some computer input or output sensors wear out and should be replaced as necessary.

The oxygen sensor is a computer input sensor that can waste 10% or more of your fuel economy in as short of time as 50,000 miles and is recommended at 60,000 miles by most manufacturers.

Don't forget, I mentioned just one computer component, and there are many more on any vehicle made today such as knock sensors, manifold absolute pressure sensors, temperature sensors, and on and on. These sensors are generally checked every time you get a tune up at a reputable repair facility, and as mentioned before, they can save you at the fuel pump or possibly from other costly repairs, Happy Motoring!