C 1500 Truck 2WD V8-5.3L VIN T (1999)
Fuel: Testing and Inspection
Alcohol/Contaminants-in-Fuel Diagnosis
Alcohol-in-fuel can be detrimental to fuel system components and may cause driveability problems such as hesitation, lack of power, stall, no start, etc.
The problems may be due to fuel system corrosion and subsequent fuel filter plugging, deterioration of rubber components, and/or air-fuel mixture
leaning. Commercial fuel uses various types and concentrations of alcohol. Some types of alcohol are more detrimental to fuel system components than
others. If you suspect an excessive amount of alcohol in the fuel as the cause of a driveability condition, use the Alcohol-in-Fuel Testing Procedure to
detect the presence of alcohol in the fuel.
Alcohol-in-Fuel Testing Procedure
Draw the fuel sample from the bottom of the tank in order to detect any water present in the tank. The sample should be bright and clear. If the sample
appears cloudy, or contaminated with water (as indicated by a water layer at the bottom of the sample), do not use this procedure. Go to Fuel System
Cleaning.
1. Fill a 100 ml cylinder with fuel to the 90 ml mark.
2. Add 10 ml of water to bring the total fluid volume to 100 ml. Install a stopper on the cylinder.
3. Shake the cylinder vigorously for 10 to 15 seconds.
4. Carefully loosen the stopper to release the pressure.
5. Close the stopper and shake the cylinder vigorously again for 10 to 15 seconds.
6. Put the graduated cylinder on a level surface for approximately 5 minutes to allow adequate 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 lower layer increases to 15 ml, it indicates 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.
