Engine Surges

If engine power varies during steady throttle operation, check the following items:

• Ensure there are no vacuum leaks.
• Check operation of thermostatic air cleaner damper door.
• Check for intermittent open or short to ground in Torque Converter Clutch (TCC).
• Ensure EGR valve operation is correct and valve closes completely.
• Ensure fuel system pressure is correct and consistent.
• Check in-line fuel filter and replace if dirty or clogged.
• Check fuel for water contamination.
• Check O2 sensor for lead or RTV sealant contamination. This will cause a high false voltage signal to ECM. ECM will respond by reducing (leaner) air/fuel ratio.
• Verify ignition timing is correct.
• Check for loose or faulty spark plug.
• Check A/C for excessive charge.
• Check spark plug wire for proper resistance, cracked boot or damage to cable.
• Check ignition timing spark advance system.
• Check for restricted exhaust.