Automatic Transmission

WARNING: Idle mixture is adjusted using propane. Do not smoke or have any open flame in the work area while performing this adjustment.

NOTE: Perform the fuel mixture adjustment with the engine at its normal operating temperature (cooling fan should cycle on and off at least once).
A propane enrichment kit is required to perform this test. Make sure that the propane bottle has an adequate quantity of gas before beginning adjustment.

Fig. 14 Intake Air Control Diaphragm:

1. Remove the vacuum hose from the air intake control diaphragm and clamp the hose closed, Fig. 14.

Fig. 22 Pinching Vacuum Hose Between Vacuum Solenoid Valve 'C' And The Vacuum Chamber:

2. Connect a tachometer to the engine.
3. Use a clamp to pinch closed the vacuum hose between frequency solenoid valve C and the vacuum chamber, Fig. 22.

Fig. 23 Idle Control Screw Initial Adjustment (Automatic Transmission):

4. Back the idle control screw out until the end is flush with the bracket, Fig. 23. With all power consumers switched OFF, (headlights, heater blower, rear window defogger, A/C, etc.), and the transmission in neutral, use the throttle stop screw to lower the idle speed to 580 rpm or less, Fig. 24.

Fig. 25 Idle Control Screw (Automatic Transmission):

5. Now adjust the idle speed back up to 630 +/- 50 rpm with the idle control screw, Fig. 25.

Fig. 24 Throttle Stop Screw Location (Automatic Transmission):

6. Adjust the idle speed (in neutral) up to 700 +/- 50 rpm with the throttle stop screw, Fig. 24.

Fig. 26 Adjustment Screw 'A' (Automatic Transmission):

7. With the parking brake set and blocks under the rear wheels, put the transmission in a drive gear. Adjust the idle speed using adjustment screw "A", Fig. 26.

Idle speed should be:

675 +/- 50 rpm (high altitude)
700 +/- 50 rpm (low altitude)

8. Shift the transmission into neutral.

Fig. 27 Adjustment Screw 'B' (Automatic Transmission):

9. If the car is equipped with A/C, switch the A/C ON, and adjust the idle to 700 +/- 50 rpm with adjustment screw 'B', Fig. 27.
10. Disconnect the air cleaner intake tube from the air intake duct.

Fig. 16 Equipment Hookup For Setting Idle Mixture Using Propane Enrichment Method:

11. Insert the hose of the propane enrichment kit about 4 inches into the intake tube, Fig. 16.

Fig. 17 Propane Volume/Engine Speed Graph:

12. With the engine idling, push the button on top of the propane device, then slowly open the propane control valve to obtain maximum engine speed. Engine speed should increase as the percentage of propane injected increases, Fig. 17. Engine speed should increase 30 +/- 10 rpm.
NOTE: Open the propane valve slowly. Too much gas at one time will stall the engine.
a. If the engine speed increases per specification, close the propane valve and re-check the idle speed.
b. If the engine speed does not increase per specification, remove the mixture screw anti-tamper cap and adjust the mixture.
13. To remove the mixture screw anti-tamper cap:
a. Close the propane valve and remove the air cleaner assembly.
b. Disconnect the vacuum hoses from the fast idle unloader.
c. Pull the throttle cable out of its bracket.
d. Remove the carburetor nuts.
e. Remove the bolt securing the steel vacuum manifold.

Fig. 18 Gaining Access To The Mixture Adjustment Screw:

f. Lift the carburetor clear of its studs, then tilt it backwards to gain access to the idle controller bracket screws, Fig. 18.
g. Remove the idle controller bracket.

Fig. 19 Mixture Adjustment Screw Location:

h. Remove the mixture adjustment screw anti-tamper cap, then re-install the idle controller bracket, Fig. 19.
i. Check the insulator block for damage (replace if necessary), then re-install the carburetor.
j. Reconnect the vacuum hose to the fast idle unloader.
k. Reinstall the air cleaner.
14. Start the engine and warm up to normal operating temperature (cooling fan should cycle on and off at least once).
15. Re-install the propane enrichment unit and re-check the mixture.
^If the propane enriched speed is too low, the fuel mixture is too rich. Turn the mixture screw in (clockwise) 1/4 turn and re-test.
^If the propane enriched speed is too high, the fuel mixture is too lean. Turn the mixture screw out (counter-clockwise) 1/4 turn and re-test.
16. Close the propane control valve and re-check the idle speed.
Idle speed should be 750 +/- 50 rpm
If idle speed is not within specification, adjust with the throttle stop screw, then repeat steps 10 and 11.
17. If the intake air temperature is below 65°C (149°F), and the mixture and idle speed are correct, remove all test equipment, reconnect all hoses, and re-install the mixture screw anti-tamper cap, adjustment is complete.
18. If the intake air temperature is above 65°C (149°F), continue with the adjustment procedure.
19. Disconnect the #5 vacuum hose from the air suction valve and plug the hose.

Fig. 20 Applying Vacuum to Hose #27 At The Vacuum Control Box:

20. Disconnect the #27 vacuum hose from the pipe end (not the vacuum control box end), and plug the pipe, Fig. 20.
21. Attach a vacuum pump to the hose and apply vacuum. The hose should hold vacuum.
a. If the hose does not hold vacuum, disconnect the electrical connector to the vacuum control box and re-test. If the hose still does not hold vacuum, replace the air leak solenoid valve and re-test.
b. If the hose holds vacuum, continue to the next step.
22. With the engine idling, depress the push button on the propane device, then slowly open the propane valve and check for vacuum at the #27 hose. Vacuum should be available. If vacuum is not available, check the air leak solenoid valve.
23. Re-connect all hoses.
24. Check the air bleed valve for proper operation.
25. Remove the propane enrichment equipment and re-connect the air cleaner intake duct.
26. Re-install the mixture adjusting screw hole cap.
27. Re-check the idle speed with the transmission selector in gear.

The idle speed should be: 730 +/- 50 rpm.

28. Re-check the idle speed with the transmission selector in the "P" or "N" position.

Idle speed should be: 750 +/- 50 rpm

29. Re-check the idle speed wirh the A/C switched On, and the transmission selector in gear.

Idle speed should be: 750 +/- 50 rpm.

30. If the idle rpm is not within specification, check out the idle control system.