Idle Speed: Adjustments
*** UPDATED BY TSB# 027089 DATAED AUGUST 1989AND
TSB# 027289 DATED OCTOBER 1989
Use the following information to properly adjust the idle speed for engine and alternator electrical load when the air conditioner, blower fan or headlights are engaged.
1) Remove the air cleaner assembly.
NOTE: Make sure the vacuum line from the intake manifold to the air cleaner in blocked off.
Figure 1:
2) Temporarily connect the single pin black "Read Memory" connector (752) and the two pin green "Test Mode" connector (F51) located under the driver's side of the dash board. See Figure 1.
3) Start the engine. Ensure proper operating temperature by waiting until the carburetor choke plate is fully open (or when the engine is not running in the fast idle warm-up mode.) Do not attempt to adjust cold.
Figure 2:
4) Using the chart and diagram in Figure 2, identify the type of transmission either manual or ECVT and perform the specified adjustments in the sequence given. See Figure 2.
Figure 3:
Fig. 3:
NOTE: For manual transmissions, step number 2, see explanation 5, Figure 3.
Manual Transmissions Only
5) Use this procedure for condition number 2 (A/C on, blower fan on, and radiator fan on, if equipped). Locate the vacuum hose which connects the solenoid on the firewall to the top of the adjustable orifice. Temporarily disconnect the vacuum hose at the adjustable orifice and block it off. Also, the adjustable orifice must be capped. See Figure 3.
NOTE: This adjustment in step 2 can only be performed while the compressor is running because when the compressor cycles off, the lever controlled by the actuator will move away from the adjusting screw.
Figure 1:
6) Verify the idle speed adjustments are correct. Turn the ignition off and disconnect the "Read Memory" and "Test Mode" connectors.
7) Reinstall the air cleaner and all hoses.
8) Start the engine and make sure the engine idles properly under all electrical and engine load conditions specified in the chart in Figure 2.
NOTE: The idle speed with the read memory end test mode connectors disconnected will be slightly higher in rpm. This condition is normal because the EFC system is controlling the idle speed.