Symptom Checks

Check the following items:

• Check secondary ignition system. See TEST JB under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.
• Check fuel delivery system. See TEST HB (natural gas vehicles) or TEST HC (except natural gas vehicles) under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.
• Check for restricted exhaust system. See TEST HF under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.
• Check PCV system. See TEST HG under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.
• Check EVAP Emission system for blockages (engine stalls) or leaks (excessive fuel odor). See SYSTEM TESTS (EVAPORATIVE EMISSIONS) in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.
• Check air intake system. See TEST HU under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.
• Check starting system. See appropriate STARTERS article in STARTING & CHARGING SYSTEMS.
• On F150 Lightning Pickup (5.4L Supercharged) models, check secondary circuits used for high speed fuel pump operation. See TEST KA , step 70)  under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.
• Check for contaminated Mass Airflow (MAF) sensor. If MAF sensor is okay, return to SYMPTOM DIAGNOSIS  to identify any additional symptoms or see TEST Z under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article and check for intermittent faults.