Engine Surges
- Ensure there are no vacuum leaks.
- Check for distortion or cracks in the fuel injector(s) plastic connecting flange(s).
- Ensure EGR valve operation is correct and that valve closes completely (if equipped).
- Check throttle valve switch (Vanagon).
- Check throttle shaft for excessive wear.
- Ensure fuel system pressure is correct and consistent.
- Ensure ignition timing is correct.