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Home >> Chevrolet >> 1986 >> Blazer 5.7 L >> Repair and Diagnosis >> Engine Performance >> System >> Fuel Injection System - TBI >> Testing >> Fuel System Pressure Test
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Fuel System Pressure Test

  1. Turn engine off and relieve fuel pressure. See FUEL SYSTEM PRESSURE RELIEF. Remove air cleaner and plug air cleaner (THERMAC) vacuum port on throttle body.
  2. Disconnect fuel line between throttle body and fuel filter. Install Fuel Pressure Gauge (J-29658) between throttle body and fuel filter. Start engine and observe fuel pressure reading.
  3. Fuel pressure should be 9-13 psi (.6-.9 kg/cm2 ). If not, see CHART A-5 (2.8L and 4.3L) or CHART A-7 (2.5L) in GENERAL MOTORS COMPUTER COMMAND CONTROL article in COMPUTERIZED ENGINE CONTROL section.
  4. After testing, relieve fuel pressure. Remove fuel pressure gauge and install fuel line between filter and throttle body. Start vehicle and watch for leaks. Remove plug from throttle body vacuum port and install air cleaner.
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