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Home >> Mercury >> 1983 >> Cougar Base, 5.0 F >> Repair and Diagnosis >> Engine Performance >> System >> Fuel Injection System - EFI >> Testing & Diagnosis >> Injector Pressure Test
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Injector Pressure Test

  1. Connect pressure gauge to fuel pressure test fitting. Disconnect coil connector from coil. Disconnect electrical lead from one injector and pressurize fuel system. Disable fuel pump by disconnecting inertia switch or fuel pump relay. Observe pressure gauge reading.
  2. Crank engine for 2 seconds. Turn ignition off. Wait 5 seconds. Observe pressure drop. If pressure drop is between 2-16 psi (.14-1.12 kg/cm2 ), injector is operating properly. Reconnect injector and activate fuel pump. Repeat procedure for other injector.
  3. If pressure drop is less than 2 psi (.14 kg/cm2 ) or more than 16 psi (1.12 kg/cm2 ), switch electrical connectors on injectors and repeat test. If pressure drop does not meet specification, replace disconnected injector with same color code, and then reconnect both injectors properly and repeat test.