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Home >> Audi >> 1996 >> A4 Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Basic Testing >> Fuel System >> Fuel Pressure Test >> Fuel System Pressure
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Fuel System Pressure

  1. Ensure fuel pump relay is okay. Ensure correct fuel filter is installed. Ensure battery voltage is at least 12 volts. Release fuel pressure. Ensure ignition is off.
  2. Connect Pressure Gauge (VAG 1318) between fuel supply and fuel return lines in engine compartment. Disconnect and plug vacuum line from fuel pressure regulator. Following VAG 1551 scan tool manufacturer's instructions, energize fuel system.
  3. Fuel pressure should be 55-61 psi (3.8-4.2 bar). If fuel pressure is within specification, perform FUEL SYSTEM RESIDUAL PRESSURE test BELOW. If fuel pressure is not within specification, replace fuel pressure regulator and perform test again.
  4. If fuel pressure is not within specification after replacing fuel pressure regulator, check for damaged fuel pump or damaged fuel lines. Repair as necessary. If fuel pressure is more than specification after replacing fuel pressure regulator, check fuel return line for damage. Repair as necessary.
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