Symptom Checks
WARNING: This page is about a different car, the 1995 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
Perform the following:
- Perform QUICK TEST. See TESTS W/CODES - EEC-IV (4.0L) article. If code is present, perform appropriate CIRCUIT TEST.
- Check RPM drop using step 2) of CIRCUIT TEST S, or power to MAP/BARO sensor using step 3) of CIRCUIT TEST S. See TESTS W/CODES - EEC-IV (4.0L) article.
- Check ignition system. See IGNITION SYSTEMS in SYSTEM/COMPONENT TESTS - EEC-IV (4.0L) article.
- Check idle speed. See IDLE SPEED & MIXTURE in ADJUSTMENTS - 4.0L article.
- Check fuel delivery and fuel pump. See FUEL SYSTEM in TESTS W/CODES - EEC-IV (4.0L) article.
- Check Positive Crankcase Ventilation (PCV) system. See EMISSION SYSTEMS & SUB-SYSTEMS in the appropriate SYSTEM/COMPONENT TESTS - EEC-IV (4.0L) article.
- Ensure engine operates at normal operating temperature.
- Check Exhaust Gas Recirculation (EGR) system. See EMISSION SYSTEMS & SUB-SYSTEMS in the SYSTEM/COMPONENT TESTS - EEC-IV (4.0L) article.
- Check engine mechanical condition. Check compression, camshaft, valve train components, intake manifold gaskets, etc.
- Check air injection. See EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM/COMPONENT TESTS - EEC-IV (4.0L) article.
- Check air intake system. Ensure throttle plate and linkages operate properly.
- Check Fuel Evaporation (EVAP) system. See EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM/COMPONENT TESTS - EEC-IV (4.0L) article.
- Check for restricted exhaust system.