Fuel Quality Diagnosis

Fuel Quality Diagnosis
Fuel quality may cause driveability problems such as hesitation, lack of power, stalling, the inability to start, etc.
For best results, use a Number 2-D diesel fuel year-round (above and below freezing conditions) as the oil companies blend Number 2-D fuel to address climate differences. Number 1-D diesel fuel may be used when the temperature falls below -18°C (0°F); however; Number 1-D diesel fuel will produce a loss in power and fuel economy. The use of Number 1-D fuel in warm or hot climates may result in stalling, poor starting when the engine is hot, damage to the fuel injection system.

Specific Gravity Testing
The fuel quality hydrometer provides a general indication of fuel quality and should not be considered to be scientifically accurate.

Fuel Oil Specific Gravity Requirements
1. Drain the fuel filter housing by following the steps below:
^ Stop the engine.
^ Place a container under the water drain valve exit hose at the left front side of the engine.
^ Open the drain valve.
^ Use a scan tool in order to command the fuel lift pump ON.
^ Fill a 1 liter (0.946 quart) container with a sample of fuel.
^ Close the drain valve.
2. Obtain a Diesel Fuel Quality Tester fuel quality hydrometer.
3. Fill the Diesel Fuel Quality Tester hydrometer with the fuel sample by doing the following:
^ Squeeze the hydrometer bulb.
^ Submerse the hydrometer tip into the sample.
^ Release the bulb, allowing fuel to enter the glass tube until it completely floats the glass bulb inside the tube.
^ Gently spin the hydrometer in order to relieve the surface tension of the fuel sample.
4. Read the scale on the glass bulb at the point where the top of the fuel sample contacts it.
^ Reading this value will indicate an approximate fuel oil specific gravity. Refer to tool instructions on how to determine Accelerator Pedal Position (APP) Gravity.
^ Refer to Fuel Oil Specific Gravity Requirements table.
5. If the correct fuel is being used in the conditions listed in Fuel Quality and meets the number 1-Diesel or the number 2-Diesel fuel oil specific gravity requirements, the fuel may be OK. If not, the fuel should be replaced.