Throttle Valve (TV) Control Linkage System (carb)

ADJUSTMENTS

Throttle Valve (TV) Control Cable System

The throttle valve (TV) control cable system consists of a cable attaching grommet on the throttle body or carburetor throttle lever, the TV control cable assembly, the external TV control lever on the transmission, and the cable mounting brackets at the throttle body or carburetor and transmission.






As the throttle is moved from idle to wide-open throttle (WOT), the TV control cable pulls the transmission TV control lever from idle to WOT. Return of the cable and transmission lever toward idle is accomplished by the return spring on the transmission end of the cable assembly. This spring and the end of the cable assembly is protected by a flexible rubber boot. The transmission external TV control lever actuates the internal TV control mechanism which regulates the TV control pressure. The travel of this lever is controlled by stops internal to the transmission.

The TV control cable is set and locked to its proper length during initial assembly when the grooved pin on the upper end of the cable assembly is inserted in the grommet on the throttle body lever. To release the cable locking mechanism, it is necessary to pry the grooved pin out of the grommet and push out the white locking pin. The take-up spring at the end of the cable assembly tensions the cable and takes up the slack in the system. When the grooved pin is reinserted in the grommet, the white locking tab is pushed in, automatically locking the cable to its correct length. When the cable is locked, the take- up spring plays no part in the operation of the system.

Under normal circumstances, it should not be necessary to alter or readjust the initial setting of the TV control cable. Situations requiring readjustment of the TV control cable include maintenance involving the removal and/or replacement of the throttle body, transmission, TV cable assembly or installing a new main control assembly. Readjustment of the TV control cable would also be necessary to correct complaints of poor transmission shift quality that would have been caused by a misadjustment of the TV control cable.

When the TV control cable is properly set, the transmission TV control lever will be at its internal idle stop (lever to rear as far as it will travel) when the throttle lever is at its idle stop.

Idle Speed Affect on TV Control Cable

The 5.OL and 5.OL HO (302 CID) SEFI engine uses an Air Bypass (ISC) that does not affect throttle position. Therefore, idle automatic setting does not affect TV cable adjustment.

TV Cable Linkage Adlustment

Self-Locking (Core Wire Adjustment)

1. Set parking brake and place shift selector in NEUTRAL position. Do not check or set TV pressure in PARK.

2. Remove air cleaner cover and inlet tube from throttle body inlet to access throttle lever and cable assembly.

3. Using a wide-blade screwdriver, pry grooved pin on cable assembly out of grommet on throttle body lever.

4. Using a small screwdriver, push out white locking tab.










5. Check to ensure plastic block with pin and tab slides freely on notched rod. If it does not slide freely, the white tab may not be pushed out far enough.






6. While holding throttle lever firmly against its idle stop, push grooved pin into grommet on throttle lever as far as it will go.

NOTE: While pushing pin into grommet, make sure you do not move throttte lever away from idle stop.

7. Install air cleaner cover and air inlet tube.






Linkage Adjustment Using Throttle Valve TV Control Pressure

Core Wire Adjustment

NOTE: This procedure requires the use of TV Pressure Gauge Set (0-60 psi) T86L-70002-A1 or equivalent. The results of the adjustment procedure depends on the accuracy of the pressure gauge.

A pressure gauge should be checked periodically (approximately every six months) or when the following occurs:

1. The needle will not return to 0 kPa (0 psi) under no pressure.

2. The needle goes past 0 kPa (0 psi) (negative side) under no pressure.

3. Bumping or dropping a pressure gauge.

Adjustment and/or Check

1. Attach TV Pressure Gauge Set (0-60 psi) T86L- 70002-Al or equivalent, to the TV port on the transmission.

NOTE: If service tool is not available, in order to avoid the exhaust system, obtain the following material and assemble as shown:

- One 1/8-inch NPT female Hansen fitting
- One 1/8-inch NPT male Hansen fitting
- One 1/4-inch NPT 90 degree elbow connector
- One high-pressure hose fitting

The pressure gauge should have 2.4m (8 feet) of flexible hose to make the gauge accessible while operating the engine.

2. Remove the air cleaner cover and inlet tube from the throttle body inlet for easier access to throttle lever.

3. Insert tapered end of the tool between the crimped slug on the end of cable and plastic notched rod, also on end of cable assembly. Push in Cable TV Gauge Tool T86L-70332-A, or equivalent forcing the crimped slug away from the plastic rod. Ensure gauge block is pushed in as far as it will go.

WARNING: THIS PROCEDURE REQUIRES WORKING IN CLOSE PROXIMITY TO THE EGR SPACER ASSEMBLY WHICH MAY BE HOT.






4. Operate engine until normal operating temperature is reached. The transmission fluid temperature should be approximately 38-72°C (100-1 50°F). Do not make pressure check if transmission fluid is cold or too hot to touch.

5. Set parking brake and place shift selector in NEUTRAL. With gauge tool in place and engine idling in NEUTRAL, the TV pressure should be between 207 and 276 kPa (30 and 40 psi).

NOTE: Do not check or set TV pressure in PARK.

6. If TV pressure meets specification in Step 5, remove gauge tool allowing cable to return to its normal idle position. With engine still idling in NEUTRAL, TV pressure must be at or near zero (less than 34 kPa (5 psi)).

7. If TV pressure does not meet specification in either or both Steps 5 and 6, remove gauge tool. Check for and replace damaged components. Adjust cable as outlined under TV Cable Adjustment-Self-Locking System.

8. heck TV pressure again. Refer to Steps 3 through 6.

9. If TV pressure still does not meet specification, it will be necessary to modify adjustment as follows.

10. Remove gauge tool and pry grooved pin out of grommet on throttle lever.






11. Mark or measure location of plastic block on notched rod.






12. Push out locking tab.






13. Using mark or measurement on plastic block as a reference, move plastic block toward throttle body mounting bracket to raise TV pressure, or move it away from bracket to lower TV pressure. Push in white locking tab to lock block in position.






14. Insert grooved pin into grommet.






15. Check TV pressure. Refer to Steps 3 through 6.

16. Repeat Steps 10 through 14, if necessary.

NOTE: For best transmission function, the TV pressure should be set as close as possible to 227 kPa (33 psi) in NEUTRAL with gauge toot installed. Since the TV pressure goes up approximately 14 kPa (2 psi) when the shift lever is moved from NEUTRAL to a forward gear (� or D), this will result in a TV pressure setting near the desirable 241 kPa (35 psi) in forward gear. Do not attempt to check TV pressure with the transmission in gear. When the gauge tool is removed, the TV pressure should drop to less than 34 kPa (5 psi). If the TV pressure does not drop to less than 34 kPa (5 psi), reset the TV pressure to a value less than 227 kPa (33 psi) with gauge tool installed but no less than 207 kPa (30 psi). Verify that the TV pressure is less than 34 kPa (5 psi) with gauge tool removed.