Possible Cause & Correction

Check following items:

• Ensure air filter and fuel filter are not plugged. Replace if necessary. Check for incorrect fuel pressure.
• Check for proper operation of thermostatic air cleaner damper door.
• Ensure initial ignition timing is properly set.
• Check for proper operation of TCC or VCC system.
• Check ESC system for excessive retard.
• Check EST system for proper operation.
• Ensure EGR valve is not open all the time.
• Check exhaust system for restrictions, such as a damaged or collapsed pipe, muffler or catalytic converter.
• Check charging system output. Repair charging system if voltage is less than 9 volts or more than 17 volts.
• Check for A/C clutch cutout at wide open throttle.
• Check MAP sensor output.
• Using Spark Tester (ST-125), check for available secondary voltage.
• Check engine valve timing and compression.
• Check ECM grounds for clean, tight connections.
• Check for a worn camshaft.
• Check for excessive fuel additives.