Shadow L4-153 2.5L SOHC Turbo (1989)
Idle Speed: Testing and Inspection
1.
With vehicle on PARK (A/T) or NEUTRAL (M/T), START the engine and allow it to warm up until the cooling fan cycles at least once, then shut
OFF engine.
2.
Connect a tachometer to the engine.
3.
Disconnect the 3/16" manifold vacuum purge vacuum line from the top of the throttle body and cap the nipple.
4.
Connect the scan tool to the engine compartment diagnostic connector. START the engine and allow it to idle for at least one minute.
5.
Using the scan tool, go to the Engine Running Test #70 (press and hold the ATM button with the read/hold switch in the read position).
6.
Switch the read/hold switch to the hold position and the following will occur:
a. Automatic Idle Air Speed (AIS) motor will fully close.
b. Idle spark advance will become fixed.
c. The engine rpm will be displayed on the scan tool.
7.
Check the idle rpm with a tachometer. If the idle rpm is within the specifications listed below, the throttle body minimum air flow is correct. If it
is not within the rpm range below, clean the throttle body and retest. See: Fuel Delivery and Air Induction/Throttle Body/Service and
Repair/Throttle Body Cleaning
ODOMETER READING IDLE SPEED
Less than 1000 miles 600-900 RPM
More than 1000 miles 650-900 RPM
7.
Shut OFF the engine; remove the scan tool, and tachometer; and reconnect the purge line to the throttle body.