Sufficient Clean Fuel

PURPOSE
The purpose of this test is to see if the fuel system is getting sufficient clean fuel to operate correctly.

RECOMMENDED PROCEDURE
Route a hose from the fuel drain line to a clear container and open the drain. Idle the engine and observe the fuel flowing into the container. Stop idling the engine when the container is half full.

Inspect WATER IN FUEL lamp while cranking. If the lamp is illuminated the fuel is probably contaminated with water.

Flow out of the drain should be a steady stream. Insufficient flow could indicate fuel supply or fuel system problems.

Inspect fuel in the container, it should be straw colored but not cloudy. It also should be free of water and contaminants. Dyed red or blue fuel indicates off-highway fuel.

Fuel Filter Drain:

If engine oil is present in the fuel it may indicate an injector O-ring leak and subsequent loss of rail pressure. If that is suspected, check rail pressure during engine cranking.

Some sediment and water may be present in the fuel sample if the fuel filter has not been serviced for a prolonged period of time and/or if the sediment and water have not been drained recently. If that is the case a second sample may be required to determine fuel quality.

POSSIBLE CAUSES (LOW OR NO FUEL FLOW)
- No fuel in tank.
- If equipped with a fuel line valve, it could be shut off.
- If equipped with dual tanks, the switch valve could be faulty.
- The fuel feed line could be broken or crimped, the fuel could be jelled (most likely in cold weather with No. 2 fuel).
- The screen in tank could be clogged.

NOTE: Cloudy fuel indicates that the fuel may not be a suitable grade for cold temperatures. Excessive water or contaminants may indicate that the tank and fuel system may need to be flushed and cleaned.

TOOLS REQUIRED
Clear container - approximately 1 quart