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BOSCH Cis Fuel Injection -- BMW: Testing: Injectors

  1. Install Pressure Tester (13 3 060) to measure fuel pressure applied to injector(s). Remove injector(s). Carefully lift sensor plate with magnet or pliers. Observe injector tips. Injectors are good if no more than one drop leaks from tip every 15 seconds. Replace defective injector(s).
  2. Open 2-way valve for flow-through operation. Turn ignition ON. Unplug connector at mixture control unit. Lift sensor plate for about 4 seconds maximum.
  3. System pressure should not drop more than 4 psi (.3 kg/cm2 ). If pressure drop is more than 4 psi, check for a restricted/blocked fuel filter, improper fuel pump delivery rate, or low fuel level in fuel tank.