Fuel Injectors & Pumps

Section 6.12 White Smoke Problem

Section 6.12
White Smoke Problem

To determine if an improper grade of fuel is causing excessive white smoke, perform the following:‪

  1. Acquire a fuel oil sample from the vehicle fuel tank(s).
  2. Submit fuel oil sample for testing.
  3. If evidence of improper grade fuel in system, follow these steps to resolve the concern:
    1. Drain the fuel tanks; refer to OEM guidelines, and dispose of properly.
    2. Refill the fuel tanks with new fuel oil having a cetane number greater than 45.
    3. Test operation.

To determine if aerated fuel is causing excessive white smoke, perform the following steps:‪

  1. Disconnect the fuel line return hose from the fitting located at the fuel tank; refer to OEM guidelines.
  2. Place the open end of the fuel line into a suitable container.
  3. Start and run the engine at 1000 rpm.
  4. Visually check to see if air bubbles are rising to the surface of the fuel within the container.
  5. If evidence of aerated fuel in system, follow these steps to resolve them:
    1. Tighten all fuel line connections between fuel tank and fuel pump; refer to OEM guidelines.
    2. Visually inspect all fuel lines between fuel tank and fuel pump for leaks (fuel pump problems can cause white smoke conditions, see Series 60 service manual (6SE483) or Series 50 service manual (6SE50) for fuel pump testing).
    3. Repair damaged components as required; refer to OEM guidelines.
    4. Verify aerated fuel resolution.
    5. If air bubbles are not present, shut down engine, check for improper injector calibration setting.


Unit Fuel Injectors and Unit Pumps Technician's Guide - 7SE500
Generated on 10-13-2008

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