XL-7 2WD V6-3.6L (2007)
Fuel: Testing and Inspection
Alcohol/Contaminants-In-Fuel Diagnosis (W/O Special Tool)
Alcohol/Contaminants-in-Fuel Diagnosis (w/o Special Tool)
Diagnostic Instructions
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Perform the Diagnostic System Check See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System Check - Vehicle
Diagnostic InformationVehicle Diagnostic Information prior to using this diagnostic procedure.
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Review Strategy Based Diagnosis for an overview of the diagnostic approach. See: Testing and Inspection/Initial Inspection and Diagnostic
Overview/Strategy Based Diagnosis
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Diagnostic Procedure Instructions - Vehicle Diagnostic Information provides an overview of each diagnostic category.
Description
Water contamination in the fuel system may cause driveability conditions such as hesitation, stalling, no start, or misfires in one or more cylinders. Water
may collect near a single fuel injector at the lowest point in the fuel rail, and cause a misfire in that cylinder. If the fuel system is contaminated with
water, inspect the fuel system components for rust, or deterioration. Alcohol concentrations more than 10 percent in the fuel can be detrimental to fuel
system components. Alcohol contamination may cause fuel system corrosion, deterioration of rubber components, and subsequent fuel filter restriction.
Fuel contaminated with alcohol may cause driveability conditions such as hesitation, lack of power, stalling, or no start. Some types of alcohol are more
detrimental to fuel system components than others.
Alcohol in Fuel Testing Procedure
The 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 alcohol contamination is suspected then use the following procedure to test the fuel quality.
1. Using a 100 ml (3.38 oz) specified cylinder with 1 ml (0.34 oz) graduation marks, fill the cylinder with fuel to the 90 ml (3.04 oz) mark.
2. Add 10 ml (0.34 oz) of water in order to bring the total fluid volume to 100 ml (3.38 oz) and install a stopper.
3. Shake the cylinder vigorously for 10-15 seconds.
4. Carefully loosen the stopper in order to release the pressure.
5. Re-install the stopper and shake the cylinder vigorously again for 10-15 seconds.
6. Put the cylinder on a level surface for approximately 5 minutes in order to allow adequate liquid separation.
If alcohol is present in the fuel, the volume of the lower layer, that now contains both alcohol and water, will be more than 10 ml (0.37 oz). For
example, if the volume of the lower layer is increased to 15 ml (0.51 oz), this indicates at least 5 percent alcohol in the fuel. The actual amount of
alcohol may be somewhat more because this procedure does not extract all of the alcohol from the fuel.
Particulate Contaminants in Fuel Testing Procedure
The fuel sample should be drawn from the bottom of the tank so that any contaminants 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 water layer at the bottom of the sample, use the following procedure
to diagnose the fuel.
1. Using an approved fuel container, draw approximately 0.5 liter (0.53 qt) of fuel.
2. Place the cylinder on a level surface for approximately 5 minutes in order to allow settling of the particulate contamination.
Particulate contamination will show up in various shapes and colors. Sand will typically be identified by a white or light brown crystals. Rubber will
appear as black and irregular particles. If particles are found, clean the entire fuel system thoroughly. Refer to Fuel System Cleaning.
