50 States

NOTE: With YFA-1V Feedback Carburetor (FBC), Direct Current (DC) Motor Idle Speed Control (ISC) - Curb Idle Speed and Fast Idle Speed Checks/Adjustments.

Instructions:

NOTE: If curb Idle is NOT within specification after performing this procedure, it will be necessary to perform the appropriate FBC Electronic Engine Controller (EEC-IV) diagnostic procedure.

1. Preliminary Procedure:
a. Block wheels, apply parking brake, and bring engine to normal operating temperature.
b. Remove air cleaner, disconnect and plug vacuum line at bottom of air cleaner.
c. Turn off all accessories.

NOTE: After adjustments are completed, reconnect all parts.

2. Closed Throttle Plate Speed Adjustment (KILL SPEED):
a. Simultaneously hold throttle OPEN to maintain 1,000 Revolutions Per Minute (RPM) while pressing lightly on the ISC motor shaft.
b. After shaft retracts completely, RELEASE throttle and quickly unplug ISC motor connector.
c. Run engine for 60 seconds on the kickdown step (second highest step) of the fast idle cam.
d. If electric cooling fan comes ON during KILL SPEED, set procedure, DISCONNECT power lead and proceed.
e. Check closed plate RPM (700±25 rpm) while in NEUTRAL.

YFA-1V FB w/ISC:

f. If adjustment is required, remove tamper resistant cap using pliers/screwdrivers. Adjust RPM's to specification by turning throttle plate stop screw.
3. Idle Speed (Cannot be adjusted - EEC-IV Controlled):
a. All accessories OFF.
b. Verify engine idle speed as specified on emission decal.
c. If speed is not within specification, refer to the 2.3L OHC EEC-IV diagnostic procedure.
d. If the idle speed is revised per the diagnostic procedure, the bowl vent set must be checked and adjusted if necessary, as specified below:
^ Allow engine to run at Curb Idle with transmission in position specified on decal.
^ Disconnect ISC electrical connector, engine should remain at Curb Idle RPM.
^ Turn engine OFF, throttle position will not change.

YFA-1V FB And Non-FB Bowl Vent Check/Adjust:

^ OPEN throttle so that the throttle vent lever does not touch the bowl vent rod, (see illustration). CLOSE the throttle to the idle set position, and measure the travel of the fuel bowl vent rod from the OPEN throttle position, (Dimension A).
^ Travel of the bowl vent rod (Dimension A), should be within specification (0.100 to 0.150 inches).
^ If OUT-of-specification, bend the throttle vent lever at notch, to obtain required travel.
^ Remove all test equipment, reconnect ISC electrical connector, and reinstall air cleaner assembly. Tighten holddown bolt to specification.
4. Kickdown Speed Adjustment:
a. DISCONNECT the purge solenoid electrical connector.
b. DISCONNECT and cap EGR vacuum line.
c. Turn all accessories OFF.
d. RUN engine on kickdown step (second highest step) of cam for 30 seconds.
e. Verify kickdown as specified on emission decal.
f. Adjust, if necessary.
5. DC Motor Maximum Extension RPM
a. DISCONNECT the purge solenoid electric connector.
b. DISCONNECT and cap EGR vacuum line.
c. Turn all accessories OFF.
d. START engine and idle for 30 seconds.
e. Place throttle ON kickdown step. Verify DC motor has fully EXTENDED. DISCONNECT ISC motor.
f. OPEN the throttle to come OFF the kickdown step, take throttle lever OFF kickdown and then CLOSE the throttle to contact the DC motor. Check engine RPM.
^ RPM between 1,400 and 2,200 for A/T.
^ RPM between 1,400 and 2,200 for M/T.
g. If necessary, adjust ISC maximum extension RPM to specification using an Allen wrench. The maximum extension adjusting screw has a jam nut, it is important to tighten the jam nut to 25 in-lbs after setting the maximum extension screw.