Symptom Checks

Perform the following:

• Check cooling system. If cooling system is overheating, go to ENGINE RUNS HOT (OVERHEATING) symptom.
• On models with Distributor Ignition (DI), check base timing. See ADJUSTMENTS - 4.0L article.
• Check engine mechanical condition. Check compression, camshaft, valve train components, etc.
• Check fuel delivery system. See FUEL SYSTEM in appropriate SYSTEM/COMPONENT TESTS - EEC-IV (4.0L) article.
• Check Exhaust Gas Recirculation (EGR) system. See EMISSION SYSTEMS & SUB-SYSTEMS in the SYSTEM/COMPONENT TESTS - EEC-IV (4.0L) article.
• Check Positive Crankcase Ventilation (PCV) system. See EMISSION SYSTEMS & SUB-SYSTEMS in appropriate SYSTEM/COMPONENT TESTS - EEC-IV (4.0L) article.
• Check air injection. See EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM/COMPONENT TESTS - EEC-IV (4.0L) article.
• Ensure transmission is functioning properly.