Fuel Injectors: XL-7
- Using a mechanic's stethoscope, check each fuel injector for operating "clicking" sound as engine is cranked. If all fuel injectors made operating sound, go to next step. If any one or all fuel injectors do not make operating sound, go to step 3 .
- Turn ignition off. Disconnect ECM harness connectors C51-2 and C51-3. ECM is located under instrument panel, behind glove box. See Figure
. Using DVOM, measure resistance between specified circuits. See CHECKING FUEL INJECTOR CIRCUITS AT ECM (XL-7)
table. See Figure
. Resistance should be 14.2-14.8 ohms at 68°F (20°C). If resistance is not as specified, go to next step. If resistance is as specified, substitute ECM with known good unit and retest system.CHECKING FUEL INJECTOR CIRCUITS AT ECM (XL-7)
Measure Between ECM Harness Connector Terminals Wire Color C51-2/1 & C51-3/4 Pink/Blue C51-2/2 & C51-3/4 Pink C51-2/8 & C51-3/4 Pink/Blue C51-2/9 & C51-3/4 Pink/Green C51-2/21 & C51-3/4 Grey/Black C51-2/22 & C51-3/4 Grey/Green - Check for short to each other in fuel injector circuits. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If problem is found, repair as necessary. After repair, retest system. If no problem is found, go to next step.
- If none of the injectors makes operating sounds, go to step 6 . Check suspect fuel injector harness connectors for poor, loose corroded or damaged terminal connections. If problem is found, repair as necessary. If no problem is found, go to next step.
- Measure resistance between fuel injector terminals. Resistance should be 14.2-14.8 ohms at 68°F (20°C). If resistance is as specified at all injectors, substitute ECM with known good unit and retest system. If resistance is not as specified at any injector, replace suspect injector. See FUEL SYSTEM in REMOVAL, OVERHAUL & INSTALLATION article.
- Turn ignition on. Using test light connected to ground, probe fuel injector harness connector terminal No. 2 (Blue/Black wire), at each injector. If test light illuminates, go to next step. If test light does not illuminate, check for open or short in Blue/Black wire between fuel injector and main relay. See Fig 1 . If problem is found, repair as necessary. After repair, retest system.
- Using test light connected to battery voltage, probe fuel injector harness connector terminal No. 1. If test light does not illuminate, check for and repair open or short in appropriate circuit between injector and ECM. After repair, retest system. If test light illuminates, repeat step 5 .