Fuel Delivery and Air Induction: Testing and Inspection

A fuel sample should be drawn from the bottom of the tank so that any water present in the tank will be detected. The sample should be bright and clear. If the sample appears cloudy or contaminated with water (as indicated by a layer at the bottom of the sample), this procedure should not be used. Instead, the fuel system should be cleaned and inspected for damage.

1. Using a 100 ml gasoline-safe container with 1 ml graduation marks, fill to the 90 ml mark with fuel to be tested.
2. Add 10 ml of water to bring the total fluid volume to 100 ml and install a leak-proof stopper.
3. Shake vigorously for 10 to 15 seconds.
4. Carefully release the stopper to release any pressure.
5. Reinstall the stopper and shake vigorously again for 10 to 15 seconds.
6. Put the graduated container on a level surface for approximately 5 minutes to allow adequate time for liquid separation.

If alcohol is present in the fuel, the volume of the lower layer (which would now contain both alcohol and water) will be greater than 10 ml. For example, if the volume of the layer is increased to 15 ml, it will indicate at least 5 percent alcohol in the fuel. The actual amount of alcohol may be somewhat greater because this procedure does not extract all of the alcohol from the fuel.