Corrado L4-1781cc 1.8L SOHC SC (PG) (1990)
Idle Speed: Testing and Inspection
Idle speed and CO content, checking/adjusting
CAUTION! Ignition timing, CO content and idle speed RPM's are inter-related and must be checked/adjusted together.
NOTE: The Oxygen sensor remains connected during checking/adjusting.
Requirements
-
engine oil temperature 80°C (176°F) minimum
-
all electrical consumers switched OFF (do not take measurements while radiator cooling fan is running)
-
A/C switched OFF
-
ignition timing OK
-
idle stabilizer valve OK, (when ignition is switched on the valve must buzz and hum)
-
exhaust system must be leak tight
Checking/adjusting
- switch OFF ignition
- connect VAG 1367 engine tester using inductive pickup VAG 1367/8 on ignition coil high tension lead
- connect SUN 105 CO tester (or EPA approved equivalent) to CO tap tube using hose adaptor VAG 1363/3
CAUTION! Hose must fit securely on CO tap tube to avoid measuring inaccuracies due to dilution or leakage.
- disconnect crankcase ventilation hose from emission control valve (arrow 1) and route such that only fresh air is drawn in
- start engine and let idle
-
will run from 1 to 4 minutes at increased engine RPM
When idle speed is reduced approx. 100 RPM
- disconnect blue coolant temperature sensor harness connector
CAUTION! Do not start engine with coolant temperature sensor disconnected. The control unit will go into open loop making accurate adjustment
impossible.
- raise engine speed in excess of 3000 RPM 3 times then let idle