Diagnostic Aids

Fuel spray may exist at fuel injector, but may not be enough to start engine. If both fuel injector and circuit are okay, fuel injector nozzle may be partly blocked.

Check the following for possible cause of fault:

• Blown EFI F-HTR Fuse
• Blown IGN Fuse
• Poor Injector Harness Connection
• Damaged Or Faulty PCM
  1. Relieve fuel system pressure. See FUEL SYSTEM PRESSURE RELEASE under FUEL SYSTEM. Install fuel pressure gauge. Turn ignition on. Fuel pump will run for about 3 seconds. If fuel pressure is 38-44 psi (2.7-3.1 kg/cm² ), go to next step. If fuel pressure is not as specified, go to CIRCUIT TEST A2-7A.
  2. Turn ignition off. Disconnect fuel pressure gauge. Unplug all 4 injector connectors. Install fuel injector tester (noid-light) to No. 1 fuel injector harness connector. Crank engine and observe noid-light. Repeat for each injector. If noid-light blinks for each injector, go to next step. If noid-light does not blink for each injector, go to step 5).
  3. Go to CIRCUIT TESTS A2-7C for fuel injector performance tests. Repair as necessary. Retest system. If fuel injectors are okay, go to next step.
  4. Test fuel for contamination. If contamination is present, clean fuel system. Retest system. If fuel system is okay, check for the following:
     • Incorrect valve timing.
     • Worn camshaft.
     • Weak valve springs.
     • Low engine compression.
     • Leaking head gasket.

     Repair as necessary. Retest system. If no problems are found, see TESTS W/O CODES article.

• If noid-light remains on for one or more injectors, go to next step. If noid-light does not remain on for any injector, go to step 7).
• Check for short to ground on affected fuel injector harness connector. Repair as necessary. If injector harnesses are okay, replace PCM. Retest system.
• Remove noid-light. Turn ignition on. Using a test light connected to ground, probe faulty fuel injector harness connector terminal No. 2 (Black/Orange wire). Repeat for each faulty injector. If test light comes on, go to next step. If test light does not come on, check for open or short in power feed circuit (Black/Orange wire). Repair as necessary. If power feed circuit is okay, replace ignition switch.
• Using a test light connected to battery positive terminal, probe remaining terminal of faulty fuel injector harness connector. Crank engine and observe test light. Repeat for each faulty injector. If test light blinks for each test, see TESTS W/O CODES article. If test light does not blink, go to next step.
• Check for open in fuel injector control circuit. See CONTROL CIRCUIT IDENTIFICATION table. Repair as necessary. If injector control circuit is okay, replace PCM. Retest system.