Diagnosis & Repair
- Check spark plugs and ignition system. See BASIC DIAGNOSTIC PROCEDURES article. Repair as necessary. If ignition system is okay, ensure ignition is off.
- Access ECM harness connectors behind glove box. Turn ignition on. Using DVOM, backprobe ECM connector and measure voltage between ground and injector terminals at ECM E14 connector. See IDENTIFYING INJECTOR TERMINALS table. If voltage is 9-14 volts for each circuit, go to step 4). If voltage is not 9-14 volts, go to next step.IDENTIFYING INJECTOR TERMINALS
Injector No. (1) Terminal No. Wire Color 1 10 Yellow 2 9 Black 3 8 Blue 4 7 Red 5 6 Green 6 5 Red/Blue 7 16 White 8 15 Black/White (1) Terminals are located in ECM E14 connector. - Disconnect injector of misfiring cylinder. Using ohmmeter, measure resistance between injector terminals. With injector temperature at 68°F (20°C), if resistance is 13.4-14.2 ohms, check for open or short circuit between ECM and injector. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair as necessary. If resistance is not 13.4-14.2 ohms, replace injector.
- Check fuel pressure. See BASIC DIAGNOSTIC PROCEDURES article. Repair as necessary. If fuel pressure is okay, check fuel injector performance. See SYSTEM/COMPONENT TESTS article. Replace as necessary.
- If all injectors are okay, check EGR system. See SYSTEM/COMPONENT TESTS article. Repair as necessary. If EGR system is okay, check MAF sensor and ECT sensor. See SYSTEM/COMPONENT TESTS article. Replace as necessary. If both components are okay, check engine compression, valve clearance and valve timing. See BASIC DIAGNOSTIC PROCEDURES article. Repair as necessary.