100S Quattro Wagon (Canada) V6-2.8L (AAH) (1992)
Idle Speed: Adjustments
NOTE: Idle speed is electronically controlled by the MPI ECM and cannot be adjusted. There are no adjustment screws, idle speed can only be
checked.
IDLE SPEED CHECKING
PRE-CHECK REQUIREMENTS
1.
Engine temperature at 185°F (85°C) minimum (operating temp.)
2.
Throttle valve in idle position
3.
Closed throttle position switch adjustment OK and operating properly
4.
All electrical consumers turned OFF
5.
A/C turned OFF
6.
Fuel pressure gauge NOT connected
7.
Radiator fan MUST NOT run while taking measurements
8.
NO diagnostic trouble codes stored in ECM fault memory
IDLE SPEED CHECKING PROCEDURE
1.
Connect engine tester VAG 1551, or suitable tachometer.
2.
START engine and let idle, idle speed must be:
^ 700 to 800 rpm
3.
IF NOT
^ Recall ECM fault memory again and perform Output Diagnosis Test Mode
^ Check for any vacuum leaks
^ Check for dirty throttle body and throttle plate
4.
Repair as needed and retest.