Mazda Trucks 1994-1998 Repair Guide

Relieving Fuel System Pressure

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Navajo & B Series Pick-up MODELS

See Figure 1

All multi-port fuel injected engines are equipped with a pressure relief valve located on the fuel supply manifold. Remove the fuel tank cap and attach fuel pressure gauge T80L-9974-B, or equivalent, to the valve to release the fuel pressure. Be sure to drain the fuel into a suitable container and to avoid gasoline spillage. If a pressure gauge is not available, disconnect the vacuum hose from the fuel pressure regulator and attach a hand-held vacuum pump. Apply about 25 in. Hg (84 kPa) of vacuum to the regulator to vent the fuel system pressure into the fuel tank through the fuel return hose. Note that this procedure will remove the fuel pressure from the lines, but not the fuel. Take precautions to avoid the risk of fire and use clean rags to soak up any spilled fuel when the lines are disconnected.

An alternate method of relieving the fuel system pressure involves disconnecting the inertia switch. Follow the procedures outlined later in this Section.



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Fig. Fig. 1: The fuel pressure relief valve (A) is located on the fuel supply manifold

MPV MODELS



2.6L Engine

See Figure 2

  1. Start the engine.
  2.  
  3. Remove the circuit opening relay connector from the relay box, located in the right side of the engine compartment.
  4.  
  5. After the engine stalls, turn the ignition switch OFF and reinstall the relay connector.
  6.  



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Fig. Fig. 2: Circuit opening relay connector location

3.0L Engine

See Figure 3


CAUTION
Fuel injection systems remain under pressure after the engine has been turned OFF. Properly relieve fuel pressure before disconnecting any fuel lines. Failure to do so may result in fire or personal injury.


CAUTION
Do not allow fuel spray or fuel vapors to come in contact with a spark or open flame. Keep a dry chemical fire extinguisher nearby. Never store fuel in an open container due to risk of fire or explosion.

  1. Start the engine.
  2.  
  3. Disconnect the fuel pump relay connector, located at the ECM.
  4.  
  5. After the engine stalls, turn the ignition switch OFF .
  6.  
  7. Connect the fuel pump relay connector.
  8.  



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Fig. Fig. 3: Fuel pump connector location

 
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