Common Signs Of Problems With Fuel Systems

Some of the questions below may seem silly but in fact the fuel injection pump is usually the last piece of the system to fail. Proper troubleshooting and system testing can save both time and money.

Hard Starting, White Smoke

  • Modern blends of both gasoline and diesel fuel tends to break down with age. The storage of small quantities, exposure to heating and cooling cycles and high humidity will accelerate the degradation of the fuel.
  • Be sure to keep gasoline and diesel fuels in properly labeled containers and keep only the quantity that can be used in a short period of time.
  • Do not mix gasoline and diesel fuel. The introduction of gasoline even a small quantity into a diesel fuel system can cause major damage to the system components.

Black Smoke

  • Restricted air intake systems can cause black engine smoke. This black smoke is sometimes confused with a failed fuel injection pump or injectors. Always check the air filter first if black smoke is present.
  • Excessive engine loading can also result in black smoke. Remove the loads such as disengaging clutches or reduce hydraulic loads, check hydraulic system pressures, shift to a lower gear etc.

No Start Situations

  • Is there actually fuel in the tank?
  • Is it the correct fuel for the engine?
  • Is it fresh with no contaminants?
  • Is there a leaking or blocked fuel pickup tube in the fuel tank?
  • Is the return line to the fuel tank blocked?
  • Is the fuel making it to the fuel injection pump?
  • Are the fuel filters clogged? Check for a plugged primary and secondary filter.
  • Is the mechanical or electric fuel lift pump working?
  • Check all fuel lines on the suction side of the injection pumps for air leaks.
  • Is the engine starter turning the engine fast enough?
  • If the fuel injection pump has an electric stop solenoid check it for proper operation.