Diagnosis & Repair

Check vacuum hoses for leaks, blockage and proper routing. Also, check wiring and connectors for damage or poor connections. If problem exists, repair as necessary and perform TEST DRIVE CONFIRMATION . If problem does not exist, go to next step.
Check spark and ignition system. See IGNITION CHECKS in BASIC DIAGNOSTIC PROCEDURES article. If problem exists, repair as necessary. If problem does not exist, go to next step.

Access ECM behind glove box. Turn ignition on. Using DVOM, backprobe ECM connector and measure voltage between ground and fuel injector terminals at specified ECM connector. See IDENTIFYING FUEL INJECTOR TERMINALS table. See Figure. If voltage is 9-14 volts at each terminal, go to step 5. If voltage is not 9-14 volts at each terminal, go to next step.

IDENTIFYING FUEL INJECTOR TERMINALS

Fuel Injector No.

Terminal No.

Wire Color

5 ⁽¹⁾

Yellow

6 ⁽¹⁾

Black

1 ⁽²⁾

Blue

2 ⁽²⁾

Red

3 ⁽²⁾

Green

4 ⁽²⁾

Red/Blue

5 ⁽²⁾

White

6 ⁽²⁾

Black/White

⁽¹⁾	Terminal is located in ECM harness connector E13. See Figure.

⁽²⁾	Terminal is located in ECM harness connector E14. See Figure.

Disconnect fuel injector harness connector at misfiring cylinder. Measure resistance between fuel injector terminals (component side). Resistance should be 13.4-14.2 ohms at 68°F (20°C). If resistance is as specified, repair open or short in power circuit to fuel injector or in wiring harness between ECM and fuel injector. See appropriate wiring diagram in WIRING DIAGRAMS article. If resistance is not as specified, replace fuel injector.
Check fuel pressure. See FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES article. If fuel pressure is not within specification, repair as necessary. If fuel pressure is within specification, go to next step.
Check fuel injectors. See FUEL SYSTEM in appropriate SYSTEM & COMPONENT TESTING article. If problem exists, repair as necessary. If problem does not exist, go to next step.
Check Mass Airflow (MAF) meter and Engine Coolant Temperature (ECT) sensor. See ENGINE SENSORS & SWITCHES in appropriate SYSTEM & COMPONENT TESTING article. If problem exists, replace appropriate sensor(s). If problem does not exist, go to next step.
Check engine compression. See BASIC DIAGNOSTIC PROCEDURES article. If engine compression is okay, check valve clearance. See ON-VEHICLE ADJUSTMENTS article. If valve clearance is okay, it may be necessary to check valve timing. See appropriate article in ENGINES.