Engine - Idle-Up Adjustment, Carbureted Models with A/C
85mitsubishi02SUBJECT:
IDLE-UP ADJUSTMENT- 1985 CARBURETED MODELS WITH A/C
NO. STB-85-14-001
DATE February, 1985
MODEL 1985 Cordia/Tredia
PURPOSE This bulletin contains procedures and specifications for adjusting the idle-up speed in designated models equipped with air conditioning. Three procedures are given:
A Cordia/Tredia 2.0L M/T and 1.5 L Mirage without Idle Speed Control (ISC)
B. Cordia/Tredia 2.0L A/T with Idle Speed Control (ISC)
C. Montero and Truck (Gas)
PRE-ADJUSTMENT CONDITIONS-ALL Engine at normal operating temperature, all lights and accessories OFF, transaxle in NEUTRAL, parking brake firmly applied, front wheels straight ahead, and engine cooling fan NOT RUNNING (while measuring speed).
FIGURE 1:
ADJUSTMENT PROCEDURE
A. CORDIA/TREDIA AND MIRAGE WITHOUT ISC
1. Bring vehicle to pre-adjustment conditions.
2. Adjust curb idle speed to specifications in Table I using SAS 1, Fig. 1.
3. Turn on the high-beam headlights. This applies on electrical load sufficient to actuate the throttle opener.
4. Check the "throttle opener' idle speed and adjust if necessary to specifications in Table 1, using the throttle opener adjusting screw in Fig. 1.
TABLE 1: IDLE SPEED SPECIFICATIONS-1985 CORDIA/TREDIA WITHOUT ISC AND 1.5L MIRAGE
FIGURE 2:
3. Turn the headlights OFF.
4. Turn the air conditioner ON.
5. Adjust the idle-up speed to specifications in Table I, using the A/C vacuum actuator adjusting screw, Fig. 2.
NOTES: ^ Confirm operation of vacuum actuator by switching A/C OFF/ON several times.
^ A stubby screwdriver for turning the vacuum actuator adjusting screw can be made from a magnetic Phillips bit with a rubber carburetor plug for a handle.
B. CORDIA/TREDIA 2.0 L A/T WITH ISC Idle speed is controlled by the Idle Speed Control System (ISC). If engine speed drops or rises excessively when the A/C is turned on, perform the ISC/TPS adjustment as described below.
1. Bring vehicle to pre-adjustment conditions.
2. Loosen accelerator cable tension.
3. Separate the quick disconnect from the battery positive terminal for at least 15 sec. to erase the ECU memory. Then reconnect to restore power.
4. Disconnect the oxygen sensor.
5. Turn the ignition ON for at least 15 sec. and then switch to LOCK position. Disconnect the ISC motor connector.
6. Start the engine.
7. Check ignition timing and adjust as required.
NOTE: Remove and plug vacuum hoses only while checking/adjusting timing.
FIGURE 3:
8. Adjust base idle speed to 700 RPM (600 RPM 1st 300 miles) by turning the ISC adjusting screw, Fig. 3.
9. Hold engine RPM constant about 10 seconds and then return to idle. Allow engine to stabilize and then check CO. Level should be 0.1% @ 700 RPM (650 for the first 300 miles). If not within specifications, adjust as required using the MAS and ISC adjusting screws.
10. Turn the SAS (Fig. 3) clockwise until engine speed increases and then counterclockwise until engine speed no longer decreases. Then turn the SAS counterclockwise 2/3 turn and stop.
FIGURE 4:
11. Turn the engine off. At the TPS connector, connect the positive lead of your digital voltmeter to the yellow/red wire and the negative lead to ground. NOTE: Do not separate the TPS connector.
12. Turn the ignition ON and adjust TPS output voltage 0.44V +/- .02V by turning the TPS adjusting screw (Fig. 4).
13. Verify that the setting is accurate by opening and closing the throttle several times while observing the voltmeter.
14. Turn the ignition to LOCK.
15. Reconnect the oxygen sensor and ISC motor, and remove the voltmeter.
16. Adjust accelerator cable tension.
FIGURE 1:
C. MONTERO AND TRUCK (GAS)
1. Bring vehicle to pre-adjustment conditions.
2. Adjust curb idle speed to specifications in the applicable service manual, using SAS 1, Fig. 1.
3. Turn the A/C ON and adjust the idle-up speed to specifications in Table II using the throttleopener adjusting screw in Figure 1.
NOTE: Check operation of idle-up actuator by turning A/C ON/OFF several times and observing the movement of the actuating rod.
TABLE II: IDLE-UP SPEED SPECIFICATIONS-1985 MONTERO AND TRUCK (GAS)
Idle-Up Speed, RPM
Montero 900-950
Truck 850-900