Surges/Chuggles

Engine power variation under steady throttle. Feels like vehicle speeds up and slows down with no change in load or throttle position.
1. Perform visual inspection and ensure all vacuum hoses are properly routed and not leaking.
2. Ensure TCC is operating properly.
3. Check for leaks between MAF sensor and throttle body.
4. Check charging voltage and repair charging system as needed.
5. Compare speedometer reading with VSS output using suitable SCAN tool. Repair or replace damaged component if readings do not match.
6. Check operation of EGR control system. There should be no EGR at idle.
7. Check for EGR valve leaks or plugged EGR filter.
8. Check ignition timing and ensure ignition system components are satisfactory.
9. Check fuel filter and replace as needed. Perform fuel system pressure check as outlined.
10. Inspect oxygen sensor for contamination. Contaminated sensor will cause ECM to reduce amount of fuel delivery.