Toyota Corolla 1988-1997 Repair Guide

Carburetor

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See Figures 1 and 2

The carburetor is the most complex part of the fuel system. Carburetors vary greatly in construction, but they all operate basically the same way; their job is to supply the correct mixture of fuel and air to the engine in response to varying conditions.

Despite their complexity in operation, carburetors function because of a simple physical principle; the venturi principle. Air is drawn into the engine by the pumping action of the pistons. As the air enters the top of the carburetor, it passes through a venturi, which is nothing more than a restriction in the throttle bore. The air speeds up as it passes through the venturi, causing a slight drop in pressure. This pressure drop pulls fuel from the float bowl through a nozzle into the throttle bore, where it mixes with the air and forms a fine mist, which is distributed to the cylinders through the intake manifold.



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Fig. Fig. 1: Exploded view of the 4A-F carburetor air horn assembly



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Fig. Fig. 2: Exploded view of the 4A-F carburetor float bowl and throttle body assembly

There are multiple systems (air/fuel circuits) in a carburetor that make it work:



Float
 
Main Metering
 
Idle
 
Low-Speed
 
Accelerator Pump
 
Power
 
Choke system
 

The way these systems are arranged in the carburetor determines the carburetor's size and shape.

Carburetors all function in the same fashion; larger engines have larger carburetors to move more air and fuel, but the principle is still the same. Older units don't have as many external linkages and controls to manage emissions and driveability, but the principle is still the same.

It's important to remember that carburetors seldom give trouble during normal operation. Other than changing the fuel and air filters and making sure the idle speed is OK at every tune-up, there's not much maintenance you can perform on the average carburetor. Quality of fuel and presence of water in the system will affect the carburetor; dirt particles in the fuel can clog the jets and water causes rust and corrosion. If the vehicle is to be parked or stored for a long period of time, drain the carburetor to prevent the evaporating fuel from gumming up the system.

The carburetors used on 4A-F engines are conventional 2 bbl, downdraft types similar to domestic carburetors. The main circuits are: primary, for normal operational requirements; secondary, to supply high speed/high load fuel needs; float, to supply fuel to the primary and secondary circuits; accelerator, to supply fuel for quick and safe acceleration; choke, for reliable starting in cold weather; power valve, for fuel economy.

It is important to know that carburetors seldom give trouble during normal operation. Other than changing the fuel and air filters and making sure the idle speeds are correct at every tune-up, there's not much maintenance you can perform on the average carburetor.

PRELIMINARY ADJUSTMENTS



The following adjustments are to be made with the carburetor removed from the engine. Adjustments on carburetors interrelate; if you change one setting you may affect other adjustments. Therefore, these procedures must be performed in the order presented. Read these procedures thoroughly before continuing.

Float

See Figures 3, 4, 5, 6, 7 and 8

It will be necessary to remove the air horn from the carburetor to gain access to the float. Follow the procedures outlined in the carburetor overhaul.

  1. Remove the float, needle valve, spring and plunger.
  2.  
  3. Remove the pin clip from the needle valve.
  4.  
  5. Install the needle valve, spring, and plunger onto the seat.
  6.  



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Fig. Fig. 3: Installing the float and pivot pin to the side of the carburetor

  1. Install the float and pivot pin.
  2.  
  3. Allow the float to hang down on its own weight. Check the clearance between the float tip and the air horn without the gasket on the air horn. Float level should be 0.283 inch (7.2mm).
  4.  



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Fig. Fig. 4: With the float hanging, check the clearance between the float tip and air horn

  1. Adjust if necessary, by bending the portion of the float lip marked (A) in the illustration.
  2.  



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Fig. Fig. 5: Bend the portion of the float lip marked (A) to adjust the float

  1. Lift up the float and check the clearance between the needle valve plunger and the float lip. Clearance should be 0.0657-0.0783 inch (1.67-1.99mm).
  2.  



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Fig. Fig. 6: Lift up the float and check the clearance between the needle valve plunger and the float lip

  1. If not within specification, adjust by bending the portion of the float lip marked (B) in the illustration.
  2.  



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Fig. Fig. 7: Adjust the float lip by bending the portion marked (B)

  1. After adjusting the float level, remove the float, plunger, spring and needle valve.
  2.  
  3. Assemble the pin clip onto the needle valve.
  4.  



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Fig. Fig. 8: Assemble the pin clip onto the needle valve

  1. Install the needle valve assembly, float and pivot pin. Assemble the carburetor following the procedures in the carburetor overhaul.
  2.  

Throttle Valve Opening

See Figures 9, 10 and 11

You will need the use of SST 09240-00014 and 09240-00020 or equivalent angle gauge to make any adjustments.

  1. Check the full operating angle of the primary throttle valve. The angle should be 90° from horizontal plane.
  2.  
  3. If adjustment is necessary, bend the first throttle lever stopper.
  4.  



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Fig. Fig. 9: To adjust the full operating angle of the throttle valve, bend the first throttle lever stopper

  1. Check the full opening of the secondary throttle valve. Standard and is 80° from horizontal plane.
  2.  



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Fig. Fig. 10: Check the full opening of the secondary throttle valve from horizontal plane



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Fig. Fig. 11: Adjusting the secondary throttle lever stopper

  1. Adjust if necessary by bending the secondary throttle lever stopper.
  2.  

Kick-Up Setting

See Figures 12 and 13

You will need the use of SST 09240-00014 and 09240-00020 or equivalent angle gauge to make any adjustments.

  1. With the primary throttle valve fully opened, check the clearance between the secondary throttle valve and body. the clearance should be 0.00630.0106 inch (0.16-0.27mm).
  2.  



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Fig. Fig. 12: Check the clearance between the secondary throttle valve and body for the kick-up setting

  1. Adjust by bending the secondary throttle lever if necessary.
  2.  



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Fig. Fig. 13: Adjust the kick-up setting by bending the secondary throttle lever

Secondary Touch Angle

See Figures 14 and 15

You will need the use of SST 09240-00014 and 09240-00020 or equivalent angle gauge to make any adjustments.

  1. Check the primary throttle valve opening angle when the first kick lever touches the second kick lever.
  2.  



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Fig. Fig. 14: You will need the use of an angle gauge to make any adjustments for the secondary touch angle

  1. Standard angle should be 45° from horizontal plane.
  2.  
  3. Adjustment is done by bending the first kick lever.
  4.  



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Fig. Fig. 15: To adjust the secondary touch angle, bend the first kick lever

Fast Idle Setting

See Figures 16 and 17

You will need the use of SST 09240-00014 and 09240-00020 or equivalent angle gauge to make any adjustments.

  1. Set the throttle shaft lever to the first step of the fast idle cam as shown in the illustration.
  2.  



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Fig. Fig. 16: Set the throttle shaft lever to the first step of the fast idle cam

  1. With the choke valve fully closed, check the primary throttle valve angle.
  2.  
  3. Adjustment is done by turning the fast idle adjusting screw. Standard angle is 21° from horizontal plane.
  4.  



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Fig. Fig. 17: Turn the fast idle screw to adjust

Choke Unloader

You will need the use of SST 09240-00014 and 09240-00020 or equivalent angle gauge to make any adjustments.

  1. With the primary throttle valve fully opened, check the valve angel. Standard angle is 41° from horizontal plane.
  2.  
  3. If adjustment is necessary, bend the fast idle lever.
  4.  

Choke Opener
  1. Set the fast idle cam.
  2.  
  3. While holding the throttle slightly open, push the choke valve closed, and hold it closed as you release the throttle valve.
  4.  
  5. Apply vacuum to the choke opener diaphragm.
  6.  
  7. check the choke valve angle, standard angle is 74° from horizontal plane.
  8.  
  9. Adjut if necessary by bending the relief lever.
  10.  

Choke Breaker

See Figures 18, 19, 20 and 21

  1. Set the fast idle cam. While holding the throttle slightly open, push the choke valve closed, and hold it closed as you release the throttle valve.
  2.  



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Fig. Fig. 18: While holding the throttle slightly open, push the choke valve closed, and hold it closed as you release the throttle valve

  1. Fully close the choke valve and check the choke opening angle.
  2.  
  3. Apply vacuum to the choke breaker diaphragm (A).
  4.  



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Fig. Fig. 19: Apply vacuum to the diaphragm and check the choke valve angle

  1. Check the choke valve angle. The standard angle is 38° from horizontal plane.
  2.  
  3. Adjust the angler by bending the relief lever.
  4.  
  5. Apply vacuum to the choke breaker diaphragms (A) and (B).
  6.  



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Fig. Fig. 20: Apply vacuum to the choke breaker diaphragms (A) and (B)

  1. Check the choke valve angle, standard angle is 58° from horizontal plane.
  2.  
  3. Adjust by turning the diaphragm adjusting screw.
  4.  



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Fig. Fig. 21: Adjust the choke breaker by turning the diaphragm screw

Pump Stroke

See Figure 22

  1. With the choke valve fully opened, check the length of the stroke.
  2.  



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Fig. Fig. 22: Test the pump stroke with the choke valve fully opened, check the length of the stroke

  1. Standard stroke is 0.157 inch (4.0mm).
  2.  
  3. Adjust the pump stroke by bending the connecting link (A).
  4.  

Throttle Position Switch
  1. Connect ohmmeter probes to the harness and switch body.
  2.  
  3. With the throttle valve fully opened, check that there is continuity.
  4.  
  5. Slowely return the throttle valve from fully open. At the point where there is no continuity, measure the throttle valve angle. Standard angle is 9° from horizontal plane.
  6.  
  7. If not, adjust the throttle position switch using the adjusting screw.
  8.  
  9. Check for smooth operation of each component.
  10.  

FINAL ADJUSTMENTS



See Figures 23 and 24

To perform the final carburetor adjustments, the following conditions must be met:



All accessories must be off
 
The ignition timing set correctly
 
The transmission is in the Neutral range
 
Warm the engine to operating temperature
 
The float level should be even with the correct level in the sight glass.
 
Check that the choke valve opens fully.
 
Connect a tachometer. Remove the rubber cap and attach the tachometer to the positive terminal of the service connector at the IIA distributor.
 


WARNING
Some tachometers are not compatible with this ignition system, it is recommended to confirm the capability of your unit prior to use.



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Fig. Fig. 23: The float level should be even with the correct level in the sight glass



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Fig. Fig. 24: Connect the tachometer to the positive terminal of the service connector at IIA distributor

Idle Speed

See Figure 25

Adjust the idle speed by turning the idle speed adjusting screw. It should be 650 rpm on M/T and 750 rpm on A/T. Leave the tachometer attached for further adjustments.



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Fig. Fig. 25: Adjust the idle speed by turning the idle speed adjusting screw

Fast Idle

See Figures 26, 27 and 28

  1. Stop the engine and remove the air cleaner.
  2.  
  3. Plug the Air Switching (AS) hose on Federal and Canadian models, to prevent leakage of the exhaust gas. Or plug the Air Switching Valve (ASV) for California models. Plug the HIC hose to prevent rough idling.
  4.  



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Fig. Fig. 26: Make sure to plug these hoses prior to adjusting the fast idle

  1. Disconnect the hose from the TVSV (M) port and plug the (M) port.
  2.  



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Fig. Fig. 27: Disconnect the hose from the TVSV (M) port and plug the port

  1. This will shut off the choke opener and EGR systems.
  2.  
  3. Set the fast idle cam. While holding the throttle valve slightly open, pull up the fast idle cam and hold it closed as you release the throttle valve.
  4.  

Check the fast idle cam is set at the first step.



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Fig. Fig. 28: Check that the fast idle cam is set at the first step

  1. Start the engine, but do NOT depress the accelerator pedal.
  2.  
  3. Set the fast idle speed by turning the fast idle adjusting screw. Fast idle speed should be 3000 rpm.
  4.  
  5. Make the adjustment with the cooling fan off and transmission in Neutral.
  6.  

Throttle Positioner (TP) Setting
  1. Disconnect the vacuum hose fro the throttle positioner.
  2.  
  3. Adjust the TP setting speed to 900 rpm with the cooling fan off and the transmission in Neutral.
  4.  
  5. Reconnect the vacuum hose to the throttle positioner.
  6.  

Throttle Position (TP) Switch
  1. Disconnect the throttle position switch terminal.
  2.  
  3. Using an ohmmeter, place one terminal to throttle switch connector and the other to the carburetor body.
  4.  
  5. Slowley raise the engine rpms.
  6.  
  7. Adjust the throttle position switch setting speed when the ohmmeter shows continuity. The setting speed should be 1800 rpms.
  8.  
  9. Reconnect the vacuum hose to the TVSV (M) port.
  10.  

Idle Mixture Screw

See Figures 29 and 30

As stated in Engine Electrical , the Mixture Adjusting Screw (MAS) should be the very last item you try to adjust during tune-up or troubleshooting. The MAS is concealed behind a plug; the plug cannot be removed with the carburetor on the car. If adjustment is to be done, great care must be taken during removal of the plug; clearances are very tight and damage to the carburetor can occur.

  1. Tag and disconnect all hoses and linkages attached to the carburetor.
  2.  
  3. Remove the carburetor.
  4.  
  5. Plug each carburetor vacuum port to prevent entry of metal particles.
  6.  
  7. Mark the center of the MAS plug with a punch. Drill a 0.256 in. (6.5mm) hole in the center of the plug.v
  8.  



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Fig. Fig. 29: The head of the screw is only 0.04 in. (1mm) below the plug. Drill carefully and slowly to avoid damage


WARNING
The head of the screw is only 0.04 in. (1mm) below the plug-drill carefully and slowly to avoid damage.

  1. The plug may come out with the drill at this time. If not, use a small screwdriver to reach through the hole and gently turn the adjusting screw all the way in. Do NOT overtighten the screw; just tighten it until it touches bottom.
  2.  
  3. Use a 0.295 in. (7.5mm) drill to force the plug off.
  4.  
  5. Remove the adjusting screw. Inspect the tip for any damage; remove any steel particles. If the drill has damaged the top of the screw, it must be replaced.
  6.  
  7. Reinstall the adjusting screw. Turn it all the way in, just touching bottom.
  8.  
  9. Once the screw has bottomed, turn it out 3 1 / 4 turns.
  10.  



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Fig. Fig. 30: Once the screw has bottomed, turn it out 31/4 turns

  1. Reinstall the carburetor and air cleaner.
  2.  
  3. Before adjusting idle speed and mixture, ALL the following conditions must be met:
    1. Air cleaner properly installed.
    2.  
    3. Engine running at normal operating temperature.
    4.  
    5. Choke fully opened.
    6.  
    7. All accessories OFF.
    8.  
    9. All vacuum lines connected.
    10.  
    11. Ignition timing correctly set.
    12.  
    13. Transmission in neutral.
    14.  
    15. Fuel level should be approximately centered in float glass.
    16.  
    17. For Calif. vehicles, EBCV off.
    18.  

  4.  
  5. Connect a tachometer.
  6.  
  7. Start the engine.
  8.  
  9. Turn the MAS until the highest possible rpm is achieved.
  10.  
  11. Turn the idle speed adjusting screw until 700 rpm is achieved. The idle speed adjusting screw is located above and to the left (10 o'clock) of the mixture adjusting screw.
  12.  
  13. Repeat the last two steps several times. When the idle does not rise no matter how much the MAS is turned, proceed to the next Step.
  14.  
  15. Turn the MAS screw IN to set the idle to 650 rpm.
  16.  
  17. Turn the engine OFF . Remove the air cleaner.
  18.  
  19. Gently tap a new plug into place over the MAS plug. Check and adjust the fast idle speed to 650 rpm on M/T and 750 rpm on A/T transmissions.
  20.  

The method used to set the idle mixture and speed is also known as the Lean Drop Method.

REMOVAL & INSTALLATION



See Figures 31, 32, 33, 34 and 35

  1. Disconnect the negative battery cable.
  2.  
  3. Loosen the radiator drain plug and drain the coolant into a suitable container.
  4.  


CAUTION
When draining coolant, keep in mind that cats and dogs are attracted by ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain coolant into a sealable container. Coolant may be reused unless it is contaminated or several years old.

  1. Unscrew the mounting screws and remove the air filter housing. Disconnect all hoses and lines leading from the air cleaner.
  2.  



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Fig. Fig. 31: Remove the air cleaner to access the carburetor

  1. Tag and disconnect all fuel, vacuum, coolant and electrical lines or hoses leading from the carburetor.
  2.  



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Fig. Fig. 32: Tag and disconnect all fuel, vacuum, coolant and electrical lines or hoses

  1. Disconnect the accelerator linkage from the carburetor. On cars equipped with an automatic transmission, disconnect the throttle cable linkage running from the transmission.
  2.  



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Fig. Fig. 33: Disconnect the accelerator and throttle linkages from the carburetor

  1. Remove the four carburetor mounting nuts.
  2.  



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Fig. Fig. 34: Remove the four carburetor mounting nuts

  1. Lift the carburetor off the engine and place it on a clean cloth on the workbench. If desired, the insulator (base gasket) may also be removed.
  2.  
  3. Cover the inlet area of the manifold with clean rags or a plastic bag. This will prevent the entry of dust, dirt and loose parts.
  4.  



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Fig. Fig. 35: Discard the base gasket and remove the insulator; do not discard the insulator

To install:
  1. Remove the rags/bag, then place the insulator on the manifold, making sure it is correctly positioned.
  2.  
  3. Place a new gasket, insulator and base gasket on the intake manifold.
  4.  
  5. Install the carburetor, tighten the mounting nuts and reconnect all linkages.
  6.  
  7. Connect the vacuum and fuel lines and the wiring harness.
  8.  
  9. Install the air cleaner assembly, making sure it is correctly seated on the carburetor.
  10.  
  11. Refill the coolant. Connect the negative battery cable.
  12.  
  13. Start the engine and check for any leaks. Check the float level.
  14.  

OVERHAUL



See Figures 36 through 58

Efficient carburetion depends 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 disassembly and cleaning to avoid accidental interchange during assembly.

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

The following procedure is organized so that only one group of components is worked on at a time. This will help eliminate confusion of parts or sub-assemblies on the bench. Always keep parts in order; take great care not to lose small parts or clips.

  1. To remove the air horn, unscrew the air cleaner setting bolt.
  2.  
  3. Remove the fuel pipe clamp, union, fuel pipe and gaskets.
  4.  



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Fig. Fig. 36: Separate the fuel pipe clamp from the side of the carburetor

  1. Label and disconnect the vacuum hoses. Inspect them for replacement.
  2.  
  3. Remove the pump arm pivot screw and pump arm with connecting link.
  4.  



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Fig. Fig. 37: Unscrew the pump arm pivot and pump arm, remove them with the connecting linkage

  1. Disconnect the choke link.
  2.  



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Fig. Fig. 38: Disconnect the choke linkage

  1. Disconnect the choke opener linkage.
  2.  
  3. Remove the eight retaining screws along with the number plate, fuel pipe support and choke and solenoid wire clamps.
  4.  



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Fig. Fig. 39: Remove the eight air horn retaining screws

  1. Lift the air horn with gasket from the carburetor body. Throw away the old gasket.
  2.  
  3. Disconnect the solenoid valve wires from the harness.
  4.  



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Fig. Fig. 40: Carefully disengage the solenoid harness

  1. Diconnect the throttle position switch wire from the harness.
  2.  
  3. Remove the float pivot pin, float and needle valve subassembly.
  4.  



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Fig. Fig. 41: Remove the float pivot pin, float and needle valve subassembly from the body

  1. Remove the air horn gasket and discard.
  2.  
  3. Remove the needle valve seat and gasket. Discard the old gasket.
  4.  
  5. Remove the power piston retainer (1), power piston (2) and spring.
  6.  
  7. Pull out the pump plunger (3) and remove the boot.
  8.  



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Fig. Fig. 42: Remove the power piston retainer (1), power piston (2), spring and pump plunger (3)

  1. Remove the solenoid valves from the carburetor body. Discard the O-ring.
  2.  



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Fig. Fig. 43: Unscrew the solenoid valve from the side of the carburetor

  1. Remove the (a) stopper gasket, pump discharge weight, long spring and discharge large ball.
    1. Remove the (b) pump damping spring.
    2.  
    3. Using a pair of tweezers, remove the (c) plunger retainer and small ball.
    4.  

  2.  
  3. Disconnect the throttle positioner linkage.
    1. Unbolt the throttle poistioner and remove.
    2.  

  4.  



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Fig. Fig. 44: Remove the (a) stopper gasket, pump discharge weight, long spring, discharge large ball, (b) pump damping spring, (c) plunger retainer and small ball



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Fig. Fig. 45: Remove the bolts retaining the throttle positioner

  1. To remove the jets and power valve, disengage the power valve, then remove the slow jet.
  2.  



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Fig. Fig. 46: Remove the jets and power valve



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Fig. Fig. 47: Carefully remove the slow jet and set aside

  1. Remove the nut, spring washer, TP levers, washer and spring in that order.
  2.  
  3. Unscrew and separate the primary and secondary passage plugs from the body.
  4.  
  5. Remove the primary and secondary main jets with gaskets. Discard the old gaskets.
  6.  



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Fig. Fig. 48: Unscrew the primary and secondary passage plugs

  1. Unscrew the AAP housing and remove the spring and diaphragm.
  2.  



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Fig. Fig. 49: Remove the primary and secondary main jets



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Fig. Fig. 50: Separate the AAP housing with the diaphragm

  1. Remove the AAP inlet plug and small ball.
  2.  
  3. Remove the AAP outlet plug, short spring and small ball. Be careful with these small components. Do not loose or mix them up.
  4.  

  1. Remove the primary and secondary small venturies and gaskets. Discard the gaskets.
  2.  
  3. Unscrew and remove the sight glass retainer, glass and O-ring. Discard the O-ring.
  4.  



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Fig. Fig. 51: Unscrew and pull off the sight glass with the retainer and O-ring

  1. On the fast idle cam, remove the throttle return spring and throttle back spring.
    1. Remove the bolt, washer, fast idle cam, washer, arm and washer in that order for the fast idle cam subassembly.
    2.  

  2.  
  3. To remove the secondary throttle valve diaphragm, disconnect the linkage.
    1. Next, remove the two screws, diaphragm assembly and gasket.
    2.  
    3. Remove the four screws, and disassemble the cap, spring, throttle valve diaphragm, housing and retainer.
    4.  

  4.  
  5. Remove the screws retaining the throttle position switch with bracket.
  6.  
  7. To separate the body and flange, remove the screws and vacuum passage screw.
    1. Separate the body and flange. Remove the washer from the throttle valve shaft.
    2.  
    3. Remove the idle mixture and idle speed adjusting screws.
    4.  

  8.  
  9. Clean all the cast metal parts with a soft brush and carburetor solvent. Clean any carbon from around the throttle plates. Blow out all jets and passages with compressed air.
  10.  
  11. Inspect the following:
  12.  



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Fig. Fig. 52: View of the float and needle valve components



pivot pin for scratches and excessive wear (1)
 
float for a broken lip or wear in the pivot pin holes (2)
 
spring for any breaks or deformation (3)
 
plunger (5) and needle valve (4) for wear or damages
 
strainer for breaks or rust (6)
 

  1. Inspect the power piston. Make sure it moves smoothly.
  2.  



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Fig. Fig. 53: Ensure the power piston moves up and down smoothly

  1. Check for any faulty opening and closing action of the power valve.
  2.  



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Fig. Fig. 54: Test the opening and closing action of the power valve

  1. Test the fuel cut solenoid valves. Connect the wire leads to the battery terminals; you should feel a distinct click inside the solenoid as power is connected and disconnected at the battery. If this click is not felt, replace the solenoid. Replace the O-ring.
  2.  



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Fig. Fig. 55: Connect the leads of the throttle solenoid to a battery to test for proper operation

  1. Insopect the throttle position switch, connect ohmmeter probes to the switch connector and switch body.
    1. With the rod not pushed in, check that there is continuity.
    2.  
    3. With the rod pushed in, check that there is no continuity.
    4.  

  2.  
  3. insoect the coil housing. Using an ohmmeter, measure the resistance between the terminal and the coil housing. Resistance should be 17-19 ohms at 20°C. If a problem is found, replace the coil housing.
  4.  



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Fig. Fig. 56: Test the resistance of the coil housing

To assemble:

Place new gaskets and O-rings throughout the carburetor assembly.

  1. Place a new gasket in position on the flange; install the body and tighten the 3 screws.
  2.  
  3. Assmeble the carburetor body and flange.
    1. Install the idle speed adjusting and idle mixture screws.
    2.  
    3. Install the washer to the throttle valve shaft.
    4.  
    5. Place a new gasket and body onto flange.
    6.  
    7. Install a vacuum passage screw as shown in the illustration. Install the three screws.
    8.  

  4.  
  5. Install the throttle position switch and bracket with the two screws.
  6.  
  7. To install the secondary throttle valve diaphragm, assemble the housing (1), diaphragm (2), spring (3) and cap (4). Install the four screws with the retainer.
  8.  



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Fig. Fig. 57: Place the secondary throttle valve components in this order during assembly

  1. Place a new gasket into position.
  2.  
  3. Install the diaphragm assembly with two screws.
  4.  
  5. Connect the linkage from secondary throttle lever.
  6.  
  7. Install the throttle back and return springs.
  8.  

  1. To install the fast idle cam, place the washer, fast idle cam, washer, cam with washer and bolt in place.
  2.  
  3. Install a new O-ring, sight glass and sight glass retainer.
  4.  
  5. Place the primary and secondary small venturies over the new gaskets.
  6.  
  7. When attaching the AAP, install the small ball, AAP outlet plug and short spring. Next install the other small ball and AAP inlet plug.
    1. Secure the diaphragm, spring and AAP housing with the three retaining screws.
    2.  

  8.  
  9. Install the jets and power valve with new gaskets. Secure the primary and secondary passage plugs. Make sure to install new gaskets.
    1. Install the spring, washer, throttle levers with the spring washer and nuts. Install the slow jet and power valve.
    2.  

  10.  
  11. Install the throttle positioner with the two bolts. connect the throttle positioner linkage.
  12.  
  13. Install the solenoid valves with a new gasket into the carburetor gasket.
  14.  
  15. Install the check balls for the acceleration as follows. Install all discharge large ball, long spring, pump discharge weight and stopper gasket.
  16.  



Click image to see an enlarged view

Fig. Fig. 58: Place the check balls in this order

  1. Using tweezers, insert the plunger small ball and retainer.
  2.  
  3. Install the pump damping spring.
  4.  

  1. On the air horn, install the valve seat over the gasket into the fuel inlet.
  2.  
  3. Measure and adjust the float level by following the procedures outlined earlier in this section.
  4.  
  5. Install the power piston spring and piston into its bore and install the retainer.
  6.  
  7. Install the acceleration pump plunger and its boot.
  8.  
  9. Place a new gasket onto the air horn.
  10.  
  11. Install the needle valve assembly, the float and the pivot pin. Insert the float lip between the plunger and the clip when installing the float.
  12.  
  13. Install the solenoid valves with new gaskets and O-rings into the body of the carburetor.
  14.  
  15. Assemble the air horn and body. Install the eight screws, paying particular attention to the various brackets, wire clamps and steel number plate. Tighten the screws evenly, in steps, using a criss-cross pattern.
  16.  
  17. Install the accelerator pump arm. Install the pump arm to the air horn with the pump plunger hole and lever aligned.
  18.  
  19. Connect the choke link and the pump connecting link.
  20.  
  21. Install the fuel pipe and union.
  22.  
  23. With the carburetor still on the bench, move the various linkages by hand, checking for smooth operation. Follow the adjustment procedures outlined earlier.
  24.  
  25. Reinstall the carburetor on the intake manifold, following the procedure outlined earlier.
  26.  
  27. Start the engine and allow it to warm up normally. During this time, pay careful attention to the high idle speed, the operation of the choke and its controls and the idle quality. If you worked carefully and accurately, and performed the bench set-up properly, the carburetor should need very little adjustment after reinstallation.
  28.  

 
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