Fuel System
- Before checking fuel system for a no-start condition, check ignition for adequate spark. Check for proper fuel pump pressure and capacity. See BASIC FUEL SYSTEM CHECKS.
- Connect Noid Light (SA9185E) for TBI or (SA9194E) for MFI to each injector. Crank engine. If light does not light at each connector, go to step 5). If light remains on constantly for any injector, go to step 4). If light flashes at each connector, check for resistance of 1-2 ohms at each injector.
- If injector(s) resistance is not within specification, replace injector. If injector(s) resistance is within specification, check fuel quality.
- If light is on constantly for any injector, turn ignition off. Disconnect PCM connector. Turn ignition on. If noid light is still on constantly, repair short to ground in injector drive circuit between injector harness connector and PCM. If noid light is no longer on with PCM disconnected, PCM is faulty.
- Check 7.5-amp INJ fuse in underhood junction block. If fuse is okay, go to next step. If INJ fuse is blown, check for short to ground in injector power supply circuit.
- Check for power to INJ fuse with ignition on. If power is not available to fuse, check for open in battery power supply to INJ fuse. If power is available to fuse, disconnect injector harness connector(s). Check for battery voltage on Pink/Black wire(s) of injector harness with ignition on. If power is present for each injector, go to next step. If power is not present, check for open circuit between fuse and injector harness connector.
- Turn ignition off. Reconnect injector harness. Disconnect PCM connector. Turn ignition on. Check for battery voltage on injector drive circuit at PCM connector terminal J1D13 (TBI) or terminals J1D13, J1D14, J1D15 and J1D16 (MFI).
- If battery voltage is not present, repair open injector drive circuit. If battery voltage is present, check injectors for 1-2 ohms resistance. Replace injectors if not within specification. If injectors are within specification, check for PCM-to-harness contact. If contact is okay, replace PCM.
Courtesy of GENERAL MOTORS CORP.