Symptom Checks

Check the following items:

• Perform QUICK TEST. See G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section. If code is present, perform appropriate CIRCUIT TEST.
• Check ignition system. See IGNITION SYSTEMS in I - EEC-IV SYS/COMP TESTS article in the ENGINE PERFORMANCE Section.
• Check fuel delivery system. See FUEL SYSTEM in I - EEC-IV SYS/COMP TESTS article in the ENGINE PERFORMANCE Section.
• Check cooling system for overheating (hard hot start only).
• Check PCV system.
• Check Evaporative Emission (EVAP) system. See I - EEC-IV SYS/COMP TESTS article in the ENGINE PERFORMANCE Section.
• On 2.3L Mustang, check for spark. See step 25) of CIRCUIT TEST NB in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section.
• Check starting system.
• On Mark VIII, check high speed fuel pump operation. See indicated step  15 of CIRCUIT TEST XB in G - EEC-IV TESTS W/CODES article in the ENGINE PERFORMANCE Section.
• Check EGR system. See I - EEC-IV SYS/COMP TESTS article in the ENGINE PERFORMANCE Section.
• Check for contaminated MAF sensor.