Idle Problems

1. Idle speed is erratic, speed varies up and down, too high or too low, cannot be adjusted to specification
2. Warm engine has rough idle but performs OK above idle.
3. Diagnosis II — Idle problems

Quality Check

1. With fully warm engine, raise engine speed to 3000 RPM for about 5 seconds.
2. Release the throttle and let the engine return to idle.
3. Measure idle speed with a tachometer and check that:
   • The idle speed is correct
   • The idle speed does not vary more than 50 RPM
   • The idle is not rough

If test passed, return car to customer

If test failed, perform diagnosis procedure II