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Home >> Audi >> 1990 >> 100 Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Fuel System >> Fuel Control (Cis MOTRONIC) >> Fuel System Pressure
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Fuel System Pressure

  1. Ensure engine is at normal operating temperature. Connect Fuel Pressure Tester (VW 1318) to fuel distributor using Adapter (VW 1318/4). Close fuel pressure valve. See Fig 1 .
    Fig 1: Connecting Fuel Pressure Tester
    G94376Courtesy of AUDI OF AMERICA, INC.
  2. Remove fuel pump relay from fuse panel and connect Remote Control (US 4480/3) in fuse panel fuel pump relay cavity. Ensure fuse No. 13 on fuse panel is good.
  3. Open valve on pressure tester and energize fuel pump with remote control. Fuel pressure should be 89-94 psi (6.3-6.6 kg/cm2 ). If fuel pressure is too high, carefully remove fuel return line from fuel pressure regulator and place in container.
  4. Repeat test in step 3). If fuel pressure is still too high, replace fuel pressure regulator. If pressure is okay, check return line for obstruction or kinks. Repair or replace as necessary.