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Home >> Saturn >> 1991 >> SL1 Automatic >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Controls - Basic Testing >> No Start Diagnosis (A-3) >> No Start - Engine Cranks OK (PFI & TBI W/HEI Distributor, Except 4.9L CADILLAC) >> Fuel System (PFI)

Fuel System (PFI)

  1. Prior to checking fuel system for a no-start condition, check ignition for proper spark. Check for proper fuel pump pressure and capacity. See BASIC FUEL SYSTEM CHECKS.
  2. Disconnect injector harness. Turn ignition on and check for battery voltage at each injector harness. See Fig 1-Fig 5 . Battery voltage should be present on one side of each injector. If battery voltage is not present, check for blown injector power fuse. If battery voltage is present on both injector terminals, check for wires shorted together.
  3. If battery voltage is present on only one terminal, connect injector test light to injector harness. Crank engine and note light. Repeat on other injector connectors. If light flashes, check for stored ECM codes. If no codes are present, refer to appropriate HARD START symptom in TESTS W/O CODES article in this section.
  4. If light does not flash, disconnect distributor 4-wire connector. Momentarily touch test light from battery voltage to ECM RPM reference wire (circuit No. 430) of 4-wire connector. Each time test light is removed from ECM RPM reference terminal, injector test light should flash. If test light does not flash, check for open in RPM reference wire or injector drive (ground) circuit or replace faulty ECM.
Fig 1: 3.1L PFI Ignition System (Camaro & Firebird)
G92J04658Courtesy of GENERAL MOTORS CORP.
Fig 2: 4.3L, 5.0L & 5.7L TBI Ignition System (Caprice, Custom Cruiser & Roadmaster)
G92B04664Courtesy of GENERAL MOTORS CORP.
Fig 3: 5.0L TBI Ignition System (Camaro & Firebird)
G92E04665Courtesy of GENERAL MOTORS CORP.
Fig 4: 5.0L & 5.7L TBI Ignition System (Brougham)
G92G04666Courtesy of GENERAL MOTORS CORP.
Fig 5: 5.0L & 5.7L PFI Ignition System (Camaro & Firebird)
G92I04667Courtesy of GENERAL MOTORS CORP.