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    Ford Full-Size Cars 1968-1988 Repair Guide

    Carburetor

    Print

    See Figures 1, 2, 3, 4, 5, 6 and 7



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    Fig. Fig. 1: Autolite 1101-V carburetor



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    Fig. Fig. 2: Carter YF 1V carburetor



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    Fig. Fig. 3: Motorcraft 2150 2V carburetor



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    Fig. Fig. 4: Autolite 4100 4V carburetor



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    Fig. Fig. 5: Autolite/Motorcraft 4300 4V carburetor



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    Fig. Fig. 6: Motorcraft 4350 4V carburetor



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    Fig. Fig. 7: Carter Thermo-Quad carburetor

    THROTTLE SOLENOID (ANTI-DIESELING SOLENOID) TEST



    Most models are equipped with a throttle solenoid positioner. The purpose of a throttle solenoid to to prevent the engine from running on (dieseling) after the ignition is turned off. Dieseling is a common occurrence with many cars using emission control systems that require a leaner fuel mixture, a higher operating temperature, and a higher curb idle speed. The throttle solenoid prevents running-on and dieseling by closing the throttle plate(s) after the key is turned off, thereby shutting off the air and gas to the overheated combustion chamber.

    1. Turn the ignition key ON and open the throttle. The solenoid plunger should extend (solenoid energize.)
    2.  
    3. Turn the ignition OFF . The plunger should retract, allowing the throttle to close.
    4.  

    With the anti-dieseling de-energized, the carburetor idle speed adjusting screw must make contact with the throttle shaft to prevent the throttle plates from jamming in the throttle bore when the engine is turned off.

    1. If the solenoid is functioning properly and the engine is still dieseling, check for one of the following:
      1. High idle or engine shut off speed.
      2.  
      3. Engine timing not set to specification.
      4.  
      5. Binding throttle linkage.
      6.  
      7. Too low an octane fuel being used.
      8.  

    2.  
    3. Correct any of these problems as necessary.
    4.  
    5. If the solenoid fails to function as outlined, disconnect the solenoid leads. The solenoid should de-energize. If it does not, it is jammed and must be replaced.
    6.  
    7. Connect the solenoid to a 12 volt power source and to ground. Open the throttle so that the plunger can extend. If it does not, the solenoid is defective.
    8.  
    9. If the solenoid is functioning correctly and no other source of trouble can be found, the fault probably lies in the wiring between the solenoid and the ignition switch or in the ignition switch itself. Remember to reconnect the solenoid when finished testing.
    10.  

    REMOVAL & INSTALLATION



    1. Remove the air cleaner.
    2.  
    3. Disconnect the throttle cable or rod at the throttle lever. Disconnect the distributor vacuum line, exhaust gas recirculation line (1973 and later models), inline fuel filter, choke heat tube and the positive crankcase ventilation hose at the carburetor.
    4.  
    5. Disconnect the throttle solenoid (if so equipped) and electric choke assist (1973 and later models) at their connectors. Remove the wires to the carburetor on the 7200 VV.
    6.  
    7. Remove the carburetor retaining nuts. Lift off the carburetor carefully, taking care not to spill any fuel. Remove the carburetor mounting gasket and discard it. Remove the carburetor mounting spacer, if so equipped, from the intake manifold.
    8.  

    To install:
    1. Prior to installation, clean the gasket mounting surfaces of the intake manifold, spacer, (if so equipped), and carburetor. When using a spacer, use two new gaskets, sandwiching the spacer between the gaskets. If a spacer is not used, only one new carburetor mounting gasket is required.
    2.  
    3. Place the new gasket(s) and spacer (if so equipped) on the carburetor mounting studs. Position the carburetor on top of the gasket and hand-tighten the retaining nuts. Then tighten the nuts in a crisscross pattern to 10-15 ft. lbs. (13-19 Nm).
    4.  
    5. Connect the throttle linkage, the distributor vacuum line, exhaust gas recirculation line (1973 and later models), inline fuel filter, choke heat tube, positive crankcase ventilation hose, throttle solenoid (if so equipped) and electric-choke assist (1973 and later models).
    6.  
    7. Adjust the curb idle speed, the idle fuel mixture and the accelerator pump stroke (Autolite/Motorcraft 2 and 4-barrel carburetors only).
    8.  

    OVERHAUL



    Efficient carburetion depends greatly on careful cleaning and inspection during overhaul, since dirt, gum, water, or varnish in or on the carburetor parts are often responsible for poor performance.

    Overhaul your carburetor in a clean, dust free area. Carefully disassemble the carburetor, referring often to the exploded views. Keep all similar and look-alike parts segregated during the disassembly and cleaning to avoid accidental interchange during assembly. Make a note of all jet sizes.

    When the carburetor is disassembled, wash all parts (except diaphragms, electric choke units, pump plunger, and any other plastic, leather, fiber, or rubber parts) in clean carburetor solvent. Do not leave parts in the solvent any longer than is necessary to sufficiently loosen the deposits. Excessive cleaning may remove the special finish from the float bowl and choke valve bodies, leaving these parts unfit for service. Rinse all parts in clean solvent and blow them dry with compressed air or allow them to air dry. Wipe clean all cork, plastic, leather, and fiber parts with a clean, lint-free cloth.

    Blow out all passages and jets with compressed air and be sure that there are no restrictions or blockages. Never use wire of similar tools to clean jets, fuel passages, or air bleeds. Clean all jets and valves separately to avoid accidental interchange.

    Check all parts for wear or damage. If wear or damage is found, replace the defective parts. Especially check the following:

    1. Check the float needle and seat for wear. If wear is found, replace the complete assembly.
    2.  
    3. Check the float hinge pin for wear and the float(s) for dents or distortion. Replace the float if fuel has leaked into it.
    4.  
    5. Check the throttle and choke shaft bores for wear or an out-of-round condition. Damage or wear to the throttle arm, shaft, or shaft bore will often require replacement of the throttle body. These parts require a close tolerance of fit. Slight wear may allow air linkage, which could affect starting and idling.
    6.  

    Throttle shafts and bushings are not included in overhaul kits. They can usually be purchased separately.

    1. Inspect the idle mixture adjusting needles for burrs for grooves. Any such condition requires replacement of the needle, since you will not be able to obtain a satisfactory idle.
    2.  
    3. Check the bowl cover for warped surfaces with a straightedge.
    4.  
    5. Closely inspect the valves and seats for wear and damage, replacing as necessary.
    6.  
    7. After the carburetor is assembled, check the choke valve for freedom of operation.
    8.  

    Carburetor overhaul kits are recommended for each overhaul. These kits contain all gaskets and new parts to replace those which deteriorate most rapidly. Failure to replace all parts supplied with the kit (especially gaskets) can result in poor performance later.

    Some carburetor manufacturers supply overhaul kits of three basic types: minor repair; major repair; and gasket kits. Basically, they contain the following:

    Minor Repair Kits:


    All gaskets
     
    Float needle valve
     
    Volume control screw
     
    All diaphragms
     
    Spring for the pump diaphragm
     

    Major Repair Kits:


    All jets and gaskets
     
    All diaphragms
     
    Float needle valve
     
    Volume control screw
     
    Pump ball valve
     
    Float
     
    Complete intermediate rod
     
    Intermediate pump lever
     
    Some cover hold-down screws and washers
     

    Gasket Kits:


    All gaskets
     

    After cleaning and checking all components, reassemble the carburetor, using new parts and referring to the exploded view. When reassembling, make sure that all screws and jets are tight in their seats, but do not overtighten as the tops will be distorted. Tighten all screws gradually, in rotation. Do not tighten needle valves into their seats; uneven jetting will result. Always use new gaskets. Be sure to adjust the float level when reassembling.

    ADJUSTMENTS



    Automatic Choke Housing
    ALL MODELS

    By rotating the spring housing of the automatic choke, the reaction of the choke to engine temperature can be controlled. To adjust, remove the air cleaner assembly, loosen the thermostatic spring housing retaining screws and set the spring housing to the specified index mark. After adjusting the setting, tighten the retaining screws and install the air cleaner assembly to the carburetor.

    Choke Plate Pulldown Clearance
    AUTOLITE 1101
    1. Remove the air cleaner assembly.
    2.  
    3. Remove the choke cover and thermostatic coil assembly. Block the throttle valve half open so that the fast idle screw does not contact the fast idle cam.
    4.  
    5. Bend a 0.036 in. (0.9mm) wire gauge at a 90 degree angle about 1 / 8 in. (3mm) from the end. Insert the bent end between the lower edge of the choke piston slot and the upper edge of the right hand slot in the choke housing.
    6.  
    7. Move the piston lever counterclockwise until the gauge fits snugly in the slot. Hold the gauge in place by exerting light pressure on the lever.
    8.  
    9. Insert a drill or gauge of the specified thickness (see Carburetor Specifications chart) between the lower edge of the choke plate and the air horn wall.
    10.  
    11. To adjust, carefully bend the choke piston link (in an S or Z-shaped bend) until the choke plate clearance is that of the drill gauge.
    12.  
    13. After adjustment, install the choke cover and adjust it. Install the air cleaner.
    14.  

    CARTER YF
    1. Remove the air cleaner, and remove the choke thermostatic spring housing.
    2.  
    3. Bend a section of 0.026 in. (0.66mm) diameter wire at a 90 degree angle approximately 1 / 8 in. (3mm) from one end.
    4.  
    5. Insert the bent end of the wire gauge between the choke piston slot and the right hand slot in the choke housing. Rotate the choke piston lever counterclockwise until the gauge is snug in the piston slot.
    6.  
    7. Exert light pressure upon the choke piston lever to hold the gauge in position. Check the specified clearance with a drill of the correct diameter between the lower edge of the choke plate and the carburetor bore.
    8.  
    9. Choke plate pulldown clearance may be adjusted by bending the choke piston lever as required to obtain the desired clearance. It is recommended that the choke piston lever be removed prior to bending, in order to prevent distorting the piston link.
    10.  
    11. Install the choke thermostatic spring housing and gasket, and adjust the housing.
    12.  

    AUTOLITE 4100, 2100 (1968-69 MODEL YEARS)
    1. Follow Steps 1-5 for Autolite 1101 type carburetor.
    2.  
    3. Turn the adjusting nut as required until the choke plate clearance is that of the drill gauge.
    4.  
    5. After adjustment, install the choke cover and adjust it.
    6.  

    MOTORCRAFT 2100 (1970-74 MODEL YEARS)
    1. Remove the air cleaner.
    2.  
    3. With the engine at its normal operating temperature, loosen the choke thermostatic spring housing retaining screws. Set the housing 90 degrees in the right direction.
    4.  
    5. Disconnect and remove the choke heat tube from the choke housing.
    6.  
    7. Turn the fast idle adjusting screw outward one full turn.
    8.  
    9. Start the engine. Use a drill of the specified diameter to check the clearance between the lower edge of the choke plate and the air horn wall.
    10.  
    11. To adjust the clearance, turn the diaphragm stop screw (located on the underside of the choke diaphragm housing). Turning clockwise will decrease the clearance; counterclockwise will increase it.
    12.  
    13. Connect the choke heat tube, and set the choke thermostatic spring housing to the proper specification. Adjust the fast idle speed to specification.
    14.  

    MOTORCRAFT 2150
    1. Remove the air cleaner assembly.
    2.  
    3. Set the throttle on the top step of the fast idle cam.
    4.  
    5. Noting the position of the choke housing cap, loosen the retaining screws and rotate the cap 90 degrees in the rich (closing) direction.
    6.  
    7. Activate the pulldown motor by manually forcing the pulldown control diaphragm link in the direction of applied vacuum or by applying vacuum to the external vacuum tube.
    8.  
    9. Using a drill gauge of the specified diameter, measure the clearance between the choke plate and the center of the air horn wall nearest the fuel bowl.
    10.  
    11. To adjust, reset the diaphragm stop on the end of the choke pulldown diaphragm.
    12.  
    13. After adjusting, reset the choke housing cap to the specified notch. Check and reset fast idle speed, if necessary. Install the air cleaner.
    14.  

    AUTOLITE/MOTORCRAFT 4300, 4350
    1. Follow Steps 1-5 of the Autolite 1101 carburetor adjustment procedure.
    2.  
    3. To adjust, loosen the hex head screw (left hand thread) on the choke plate shaft and pry the link away from the tapered shaft. Using a drill gauge 0.010 in. (0.25mm) thinner than the specified clearance (to allow for tolerances in the linkage), insert the gauge between the lower edge of the choke plate and the air horn wall. Hold the choke plate against the gauge and maintain a light pressure in a counterclockwise direction on the choke lever. With the choke piston snug against the 0.036 in. (0.9mm) wire gauge and the choke plate against the 0.010 in. (0.25mm) smaller drill gauge, tighten the hex head screw (left hand thread) on the choke plate shaft. After tightening the hex head screw, make a final check using a drill gauge of the specified clearance between the choke plate and air horn.
    4.  
    5. After adjustment, install the choke cover and adjust.
    6.  
    7. Install the air cleaner.
    8.  

    Float Level

    AUTOLITE 1101

    See Figure 8

    1. Remove the carburetor air horn and gasket from the carburetor.
    2.  
    3. Measure the distance from the gasket surface of the air horn to the top of the float. If the measurement is not within the specified tolerance, bend the float arm tab as necessary to obtain the specified dimension. Be careful not to exert any pressure on the fuel inlet needle, as this will damage it and result in an improper fuel level within the float bowl.
    4.  
    5. Install the carburetor air horn to the main body of the carburetor, using a new gasket.
    6.  



    Click image to see an enlarged view

    Fig. Fig. 8: Float level adjustment-Autolite 1101

    CARTER YF

    See Figure 9

    Remove the carburetor air horn and gasket from the carburetor. Using a gauge made to the proper dimension, invert the air horn assembly and check the clearance between the top of the float and the bottom of the air horn. When checking the float level, the air horn should be held at eye level and the float lever arm should be resting on the pin of the needle valve. The float lever arm may be bent in order to adjust the float clearance. However, do not bend the tab at the end of the float arm, as this will prevent the float from bottoming in the fuel bowl when the bowl is empty. Using a new gasket, install the carburetor air horn.



    Click image to see an enlarged view

    Fig. Fig. 9: Float level adjustment-Carter YF

    AUTOLITE/MOTORCRAFT 2100, 2150, 4100 (DRY ADJUSTMENT)

    This preliminary setting of the float level adjustment must be performed with the carburetor removed from the engine.

    1. Remove the air horn and see that the float is raised and the fuel inlet needle is seated. Check the distance between the top surface of the main body (with the gasket removed) and the top surface of the float. Depress the float tab to seat the fuel inlet needle. Take a measurement near the center of the float, at a point 1 / 8 in. (3mm) from the free end. If you are using a prefabricated float gauge, place the gauge in the corner of the enlarged end section of the fuel bowl. The gauge should touch the float near the end, but not on the end radius.
    2.  
    3. If necessary, bend the tab on the end of the float to bring the setting within the specified limits.
    4.  

    AUTOLITE/MOTORCRAFT 2100, 2150, 4100 (WET ADJUSTMENT)

    See Figure 10

    1. Bring the engine to its normal operating temperature. Park the car on as nearly level a surface as possible, and stop the engine.
    2.  
    3. Remove the air cleaner assembly from the carburetor.
    4.  
    5. Remove the air horn retaining screws and the carburetor identification tag. Leave the air horn and gasket in position on the carburetor main body. Start the engine, let it idle for several minutes. Rotate the air horn out of the way, and remove the gasket to provide access to the float assembly.
    6.  
    7. With the engine idling, use a standard depth scale to measure the vertical distance from the top machined surface of the carburetor main body to the level of the fuel in the fuel bowl. This measurement must be made at least 1 / 4 in. (6mm) away from any vertical surface in order to assure an accurate reading.
    8.  
    9. Stop the engine before making any adjustment to the float level. Adjustment is accomplished by bending the float tab (which contacts the fuel inlet valve) up or down as required to raise or lower the fuel level. After making an adjustment, start the engine, and allow it to idle for several minutes before repeating the fuel level check. Repeat as necessary until the proper fuel level is attained.
    10.  
    11. Reinstall the air horn with a new gasket and secure it with the screws. Include the installation of the identification tag in its proper location.
    12.  
    13. Check the idle speed, mixture, and dashpot adjustments. Install the air cleaner assembly.
    14.  



    Click image to see an enlarged view

    Fig. Fig. 10: Wet float level adjustment-Autolite/Motorcraft 2100, 2150, 4100

    MOTORCRAFT 4300, 4350

    See Figures 11 and 12

    1. Refer to the illustration for construction of a tool used in checking the parallel setting of the dual pontoons.
    2.  
    3. Install the gauge on the carburetor and set it to the specified height.
    4.  
    5. Check the clearance and alignment of the pontoons to the gauge. Both pontoons should just barely touch the gauge for the proper setting. Pontoons may be aligned if necessary by slightly twisting them.
    6.  
    7. To adjust the float level, bend the primary needle tab down to raise the float and up to lower it.
    8.  



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    Fig. Fig. 11: Float level adjustment with rebuild kit gauge-Motorcraft 4300, 4350



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    Fig. Fig. 12: Float gauge and tool-Motorcraft 4300, 4350

    CARTER THERMO-QUAD
    1. Taking note of their placement, disconnect all linkages and rods which connect the bowl cover to the carburetor body.
    2.  
    3. Remove the screws retaining the bowl cover.
    4.  
    5. Remove the bowl cover. Invert the bowl cover, taking care not to lose any of the small parts.
    6.  
    7. With the bowl cover inverted and the floats resting on the seated needle, measure the distance between the bowl cover (new gasket installed) to the bottom side of each float.
    8.  
    9. If not to specifications, bend the float lever.
    10.  

    Never allow the lip of the float to be pressed against the needle when adjusting the float height.

    1. Install the bowl cover. Make sure that the float pin does not protrude past the edge of the bowl cover.
    2.  

    MOTORCRAFT 2700 VV AND 7200 VV

    See Figure 13

    1. Remove and invert the upper part of the carburetor, with the gasket in place.
    2.  
    3. Measure the vertical distance between the carburetor body (outside the gasket) and the bottom of the float.
    4.  
    5. To adjust, bend the float operating lever that contacts the needle valve. Make sure that the float remains parallel to the gasket surface.
    6.  



    Click image to see an enlarged view

    Fig. Fig. 13: Motorcraft 2700/7200 VV float level adjustment

    Float Drop
    MOTORCRAFT 2700 VV AND 7200 VV

    See Figure 14

    1. Remove and hold upright the upper part of the carburetor.
    2.  
    3. Measure the vertical distance between the carburetor body (outside the gasket) and the bottom of the float.
    4.  
    5. Adjust by bending the stop tab on the float lever that contacts the hinge pin.
    6.  



    Click image to see an enlarged view

    Fig. Fig. 14: Motorcraft 2700/7200 VV float drop adjustment

    Dechoke Clearance

    CARTER YF
    1. Remove the carburetor air cleaner.
    2.  
    3. Hold the throttle plate to the full open position while closing the choke plate as far as possible without forcing it. Use a drill of the proper diameter (see Carburetor Specifications chart) to check the clearance between the choke plate and air horn.
    4.  
    5. Adjust as necessary by bending the pawl on the fast idle speed lever. Bend forward to increase clearance and backward to decrease clearance.
    6.  

    MOTORCRAFT 4300, 4350
    1. Remove the air cleaner assembly.
    2.  
    3. Remove the automatic choke housing from the carburetor.
    4.  
    5. With the throttle plate wide-open and the choke plate closed as far as possible without forcing it, insert a drill gauge of the specified diameter between the choke plate and air horn.
    6.  
    7. To adjust, bend the arm on the choke trip lever. Bend downward to increase clearance and upward to decrease clearance. After adjusting, recheck the clearance.
    8.  
    9. Install the automatic choke housing, taking care to engage the thermostatic spring with the tang on the choke lever and shaft assembly.
    10.  
    11. Adjust the automatic choke setting. Install the air cleaner. Adjust the idle speed and dashpot, if so equipped.
    12.  

    Metering Rod

    CARTER YF

    Remove the carburetor air horn and gasket from the carburetor. Unscrew the idle speed adjusting screw until the throttle plate is tightly closed in the throttle bore. Press downward on the end of the diaphragm shaft until the metering rod arm contacts the lifter link at the diaphragm stem. With the metering rod in this position, turn the rod adjustment screw until the metering rod just bottoms in the body casting. Turn the metering rod adjusting screw one additional turn in the clockwise direction. Install the carburetor air horn along with a new gasket.

    MOTORCRAFT 2700 VV AND 7200 VV

    See Figure 15

    A dial indicator and the stator cap are required for this adjustment.

    1. Remove the choke coil cap, if equipped.
    2.  
    3. Attach a weight to the choke coil mechanism to seat the cold enrichment rod.
    4.  
    5. Install and zero a dial indicator with the tip placed on top of the enrichment rod. Raise and release the weight to verify zero on the dial indicator.
    6.  
    7. With the stator cap at the index position, the dial indicator should read the specified dimension. Turn the adjusting nut to correct it.
    8.  
    9. Install the choke cap at the correct setting.
    10.  



    Click image to see an enlarged view

    Fig. Fig. 15: Motorcraft 2700/7200 VV cold enrichment metering rod adjustment

    Accelerator Pump Stroke
    AUTOLITE/MOTORCRAFT 2100, 2150, 4100

    See Figure 16

    The accelerating pump operating rod should be in the over-travel lever hole number listed in the Carburetor Specification chart, and in the inboard hole (hole closest to the pump plunger) in the accelerating pump link. If the pump stroke has been changed from the specified settings, use the following procedure to correct the stroke:

    1. Release the operating rod from the retaining clip by pressing the tab end of the clip toward the rod while pressing the rod away from the clip until it disengages.
    2.  
    3. Position the clip over the specified hole (see Carburetor Specification chart) in the over-travel lever. Press the ends of the clip together and insert the operating rod through the clip and the over-travel lever. Release the clip to engage the rod.
    4.  



    Click image to see an enlarged view

    Fig. Fig. 16: Accelerator pump stroke adjustment-Autolite 2100, 2150, 4100

    AUTOLITE/MOTORCRAFT 4300

    The pump stroke is preset at the factory to limit exhaust emissions. The additional holes in the operating arm are provided for different engine applications. The stroke should not be changed from the specified hole (see Carburetor Specifications chart).

    The only adjustments possible are the pump stroke and pump stem height. To change the pump stroke, merely remove the pivot pin and reposition it in the specified hole. To adjust the pump stem height, bend the operating rod at the angles, taking care not to cause binds in the system.

    MOTORCRAFT 4350

    See Figure 17

    The accelerator pump adjustment is preset at the factory for reduced exhaust emissions. Adjustment is provided only for different engine installations. The adjustment is internal, with three piston-to-shaft pin positions in the pump piston.

    To check that the shaft pin is located in the specified piston hole, remove the carburetor air horn and invert it. Disconnect the accelerator pump from the operating arm by pressing downward on the spring and sliding the arm out of the pump shaft slot. Disassemble the spring and nylon keeper retaining the adjustment pin. If the pin is not in its specified hole, remove it, reposition the shaft to the correct hole in the piston assembly and reinstall the pin. Now slide the nylon retainer over the pin and position the spring on the shaft. Finally, compress the spring on the shaft and install the pump on the pump arm.

    Under no circumstances should you adjust the stroke of the accelerator pump by turning the vacuum limiter lever adjusting nut. This adjustment is preset at the factory and modification could result in poor cold driveability.



    Click image to see an enlarged view

    Fig. Fig. 17: Accelerator pump stroke adjustment-Motorcraft 4350

    Anti-Stall Dashpot
    ALL MODELS

    See Figure 18

    Make sure that the engine idle speed and mixture are correct and that the engine is at normal operating temperature. Loosen the anti-stall dashpot locknut (see accompanying illustration). With the throttle held closed, depress the plunger with a prytool and measure the clearance between the throttle lever and the plunger tip. If the clearance is not as specified in the Carburetor Specification charts, turn the dashpot until the proper clearance is obtained between the throttle lever and the plunger tip. After tightening the locknut, recheck the adjustment.



    Click image to see an enlarged view

    Fig. Fig. 18: Anti-stall dashpot adjustment

    Fast Idle Speed
    MOTORCRAFT 2700 VV AND 7200 VV
    1. With the engine warmed up and idling, place the fast idle lever on the step specified on the engine compartment sticker or in the specifications chart. Disconnect and plug the EGR vacuum line.
    2.  
    3. Make sure the high speed cam positioner lever is disengaged.
    4.  
    5. Turn the fast idle speed screw to adjust to the specified speed.
    6.  

    Fast Idle Cam Index Setting

    CARTER YF
    1. Position the fast idle screw on the kickdown step of the fast idle cam against the shoulder of the high step.
    2.  
    3. Adjust by bending the choke plate connecting rod to obtain the specified clearance between the lower edge of the choke plate and the carburetor bore.
    4.  

    AUTOLITE/MOTORCRAFT 2100 (1968-72 MODEL YEARS), 4100, 4300, 4350

    See Figure 19

    1. Loosen the choke housing retaining screws and position the housing 90 degrees to the right.
    2.  
    3. Position the fast idle speed screw at the kickdown step of the fast idle cam. This kickdown step is identified by a small V stamped in the side of the casting.
    4.  
    5. Check the clearance between the lower edge of the choke plate and the wall of the air horn by inserting a drill of the specified diameter between them. Adjustment may be accomplished by turning the fast idle cam adjusting screw clockwise to increase or counterclockwise to decrease the clearance.
    6.  
    7. Set the choke housing to specifications, and adjust the anti-stall dashpot, idle speed, and mixture.
    8.  



    Click image to see an enlarged view

    Fig. Fig. 19: Fast idle cam index setting-Autolite 2100

    AUTOLITE/MOTORCRAFT 2100, 2150 (1973 AND LATER)
    1. Loosen the choke thermostatic spring housing retaining screws and rotate the housing 90 degrees in the rich direction.
    2.  
    3. Position the fast idle speed screw or lever on the high step of the cam.
    4.  
    5. Depress the choke pulldown diaphragm against the diaphragm stop screw thereby placing the choke in the pulldown position.
    6.  
    7. While holding the choke pulldown diaphragm depressed, slightly open the throttle and allow the fast idle cam to fall.
    8.  
    9. Close the throttle and check the position of the fast idle cam lever. When the fast idle cam is adjusted correctly, the screw should contact the V mark on the cam. Adjustment is accomplished by rotating the fast idle cam adjusting screw as needed.
    10.  

    MOTORCRAFT 2700 VV AND 7200 VV

    See Figure 20

    A special tool is required for this job. Ford calls it a stator cap (#T77L-9848-A). It fits over the choke thermostatic lever when the choke cap is removed.

    1. Remove the choke coil cap. On 1980 and later California models, the choke cap is riveted in place. The top rivets will have to be drilled out. The bottom rivet will have to be driven out from the rear. New rivets must be used upon installation.
    2.  
    3. Place the fast idle lever in the specified step of the fast idle cam (the highest step is first) with the high speed cam positioner retracted.
    4.  
    5. If the adjustment is being made with the carburetor removed, hold the throttle lightly closed with a rubber band.
    6.  
    7. Turn the stator cap clockwise until the lever contacts the fast idle cam adjusting screw.
    8.  
    9. Turn the fast idle cam adjusting screw until the index mark on the cap lines up with the specified mark on the casting.
    10.  
    11. Remove the stator cap. Install the choke coil cap and set it to the specified housing mark.
    12.  



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    Fig. Fig. 20: Motorcraft 2700/7200 VV fast idle cam adjustment

    Control Vacuum

    This procedure applies only to the Motorcraft 2700 VV and 7200 VV carburetors.

    1977 MODELS
    1. Make sure the idle speed is correct.
    2.  
    3. Using a 5 / 32 in. Allen wrench, turn the venturi valve diaphragm adjusting screw clockwise until the valve is firmly closed.
    4.  
    5. Connect a vacuum gauge to the vacuum tap on the venturi valve cover.
    6.  
    7. Idle the engine and use a 1 / 8 in. Allen wrench to turn the venturi bypass adjusting screw to the specified vacuum setting. You may have to correct the idle speed.
    8.  
    9. Turn the venturi valve diaphragm adjusting screw counterclockwise until the vacuum drops to the specified setting. You will have to work the throttle to get the vacuum to drop.
    10.  
    11. Reset the idle speed.
    12.  

    1980-82 MODELS

    This procedure applies only to the Motorcraft 2700 VV and 7200 VV carburetors.

    1. Remove the carburetor. Remove the venturi valve diaphragm plug with a center punch.
    2.  
    3. If the carburetor has a venturi valve bypass, remove it by removing the two cover retaining screw. Invert and remove the bypass screw plug from the cover with a drift. Install the cover.
    4.  
    5. Install the carburetor. Start the engine and allow it to reach normal operating temperature. Connect a vacuum gauge to the venturi valve cover. Set the idle speed to 500 rpm with the transmission in Drive.
    6.  
    7. Push and hold the venturi valve closed. Adjust the bypass screw to obtain a reading of 8 in. Hg (2 kPa) on the vacuum gauge. Make sure the idle speed remains constant. Open and close the throttle and check the idle speed.
    8.  
    9. With the engine idling, adjust the venturi valve diaphragm screw to obtain a reading of 6 in. Hg (1.5 kPa). Set the curb idle to specification. Install new venturi valve bypass and diaphragm plugs.
    10.  

    Internal Vent

    This procedure applies only to the Motorcraft 2700 VV and 7200 VV carburetors.

    1978 Models

    It is required whenever the idle speed adjustment is changed.

    1. Make sure the idle speed is correct.
    2.  
    3. Place a 0.010 in. (0.25mm) feeler gauge between the accelerator pump stem and the operating link.
    4.  
    5. Turn the nylon adjusting nut until there is a slight drag on the gauge.
    6.  

    Venturi Valve Limiter

    This procedure applies only to the Motorcraft 2700 VV and 7200 VV carburetors.

    1. Remove the carburetor. Remove the venturi valve cover and the two rollers.
    2.  
    3. Use a center punch to loosen the expansion plug at the rear of the carburetor main body on the throttle side.
    4.  
    5. Use a suitable Allen wrench to remove the venturi valve wide open stop screw.
    6.  
    7. Hold the throttle wide-open.
    8.  
    9. Apply a light closing pressure on the venturi valve and check the gap between the valve and the air horn wall. To adjust, move the venturi valve to the wide-open position and insert an Allen wrench into the stop screw hole. Turn clockwise to increase the gap. Remove the wrench and check the gap again.
    10.  
    11. Install the wide open stop screw and turn it clockwise until it contacts the valve.
    12.  
    13. Push the venturi valve wide-open and check the gap. Turn the stop screw to bring the gap to specifications.
    14.  
    15. Reassemble the carburetor with a new expansion plug.
    16.  

    Control Vacuum Regulator (CVR)

    This procedure applies only to the Motorcraft 2700 VV and 7200 VV carburetors.

    There are two systems used. The earlier system's CVR rod threads directly through the arm. The revised system, introduced in late 1977, has a 3 / 8 in. nylon hex adjusting nut on the CVR rod and a flange on the rod.

    EARLY SYSTEM
    1. Make sure that the cold enrichment metering rod adjustment is correct.
    2.  
    3. Rotate the choke coil cap half a turn clockwise from the index mark. Work the throttle to set the fast idle cam.
    4.  
    5. Press down lightly on the regulator rod. If there is no down travel, turn the adjusting screw counterclockwise until some travel is felt.
    6.  
    7. Turn the regulator rod clockwise with an Allen wrench until the adjusting nut just begins to rise.
    8.  
    9. Press lightly on the regulator rod. If there is any down travel, turn the adjusting screw clockwise in 1 / 4 turn increments until it is eliminated.
    10.  
    11. Return the choke coil cap to the specified setting.
    12.  

    REVISED SYSTEM

    The cold enrichment metering rod adjustment must be checked and set before making this adjustment.

    1. After adjusting the cold enrichment metering rod, leave the dial indicator in place but remove the stator cap. Do not re-zero the dial indicator.
    2.  
    3. Press down on the CVR rod until it bottoms on its seat. Measure this amount of travel with the dial indicator.
    4.  
    5. If the adjustment is incorrect, hold the 3 / 8 in. CVR adjusting nut with a box wrench to prevent it from turning. Use an 11 / 32 in. Allen wrench to turn the CVR rod; turning counterclockwise will increase the travel, and vice-versa.
    6.  

    High Speed Cam Positioner

    This procedure applies only to the Motorcraft 2700 VV and 7200 VV carburetors.

    1979 Models
    1. Place the high speed cam positioner in the specified cam step, counting the highest step as the first.
    2.  
    3. Place the fast idle lever in the corner of the positioner.
    4.  
    5. Hold the throttle firmly closed.
    6.  
    7. Remove the diaphragm cover. Adjust the diaphragm assembly clockwise until it lightly bottoms. Turn it counterclockwise 1 / 2 -1 1 / 2 turns until the vacuum port and diaphragm hole line up.
    8.  
    9. Install the cover.
    10.  

     
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