Honda Accord/Prelude 1984-1995 Repair Guide

Carburetor

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ADJUSTMENTS



Throttle Cable

See Figure 1

  1. The throttle cable should operate smoothly with no binding. If the cable is kinked or binding, replace it.
  2.  
  3. Check the cable free play at the linkage. The cable should be loose enough to deflect 3 / 16 - 3 / 8 in. (4-10mm) between the locknut and the bell crank.
  4.  
  5. If the deflection is not correct, loosen the locknut. Turn the adjusting nut to tighten or loosen the cable as necessary. Once properly set, tighten the locknut.
  6.  
  7. Check the throttle plate while an assistant holds the accelerator pedal to the floor. The throttle should be fully open (the throttle plate should be vertical). Check carefully to see that the throttle plate is opening fully, but is not going "over center" (passing the vertical position and sitting at an angle.) Additionally, the throttle plate must close quickly and smoothly when the accelerator pedal is released.
  8.  



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Fig. Fig. 1: Throttle cable adjustment; Accord shown

Choke and Linkage

See Figure 2

  1. Remove the air cleaner.
  2.  
  3. Depress the accelerator to the floor and release it smoothly to set the choke plate(s). The plate(s) should close completely if the engine temperature is below 82°F (28°C). Above this temperature the plate(s) will not close totally, but should close to within 1 / 8 in. (3.175mm).
  4.  
  5. If choke does not close completely, check carefully for signs of dirt or binding in the linkage. Spray the linkage with carburetor cleaner and recheck.
  6.  
  7. If the choke still will not operate properly, remove the choke cover and inspect the linkage for freedom of motion. When reassembling, make certain the index marks align on the carburetor body and choke cover.
  8.  
  9. If the choke still will not operate correctly, replace the choke cover.
  10.  



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Fig. Fig. 2: The index marks must be aligned on the choke cover and housing

Fast Idle
ACCORD
  1. Start the engine and allow it to reach normal operating temperature.
  2.  
  3. With the engine off, connect a tachometer.
  4.  
  5. Disconnect and plug the inner vacuum hose from the fast idle unloader.
  6.  
  7. Engage the fast idle cam by opening and closing the throttle fully while holding the choke blade closed.
  8.  
  9. Restart the engine. Fast idle should be between 2000-3000 rpm.
  10.  
  11. If necessary, adjust the engine speed by turning the fast idle adjusting screw.
  12.  

1984-87 PRELUDE

See Figures 3, 4 and 5

  1. Start the engine and allow it to reach normal operating temperature.
  2.  
  3. With the engine off, connect a tachometer.
  4.  
  5. Remove the E-clip and flat washer from the thermowax linkage, then slide the linkage out until it is clear of the fast idle cam.
  6.  



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Fig. Fig. 3: Remove the E-clip and flat washer from the thermowax linkage, then slide the linkage out until it is clear of the fast idle cam

Be careful not to bend the linkage.

  1. Hold the throttle open and turn the fast idle cam counterclockwise until the fast idle lever is positioned as shown in the illustration.
  2.  



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Fig. Fig. 4: Hold the throttle open and turn the fast idle cam counterclockwise until the fast idle lever is positioned as shown

  1. Without opening the throttle, start the engine. Fast idle speed should be between 1250-2250 rpm for manual transaxles or 1200-2200 rpm for automatic transaxles.
  2.  
  3. Adjust, if necessary, by turning the fast idle adjusting screw.
  4.  



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Fig. Fig. 5: Adjust by turning the fast idle adjusting screw

  1. Stop the engine and reconnect the termowax linkage.
  2.  
  3. Start the engine and check that the fast idle speed decreases as the engine temperature increases. If the fast idle speed does not drop, spray the linkage with carburetor cleaner. If the speed still does not drop, check for stuck or damaged linkage components. Replace as necessary.
  4.  

1988-90 PRELUDE

See Figures 6, 7, 8 and 9

  1. Start the engine and allow it to reach normal operating temperature.
  2.  
  3. With the engine off, connect a tachometer.
  4.  
  5. Disconnect both coolant hoses from the thermowax valve and cap the ends of the hoses.
  6.  
  7. Flush the thermowax valve with cold water. Check the temperature of the water being used to flush the valve.
  8.  



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Fig. Fig. 6: Flush the thermowax valve with cold water. Check the temperature of the water being used to flush the valve

  1. Start the engine and check the engine speed. Compare it to the graph.
  2.  



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Fig. Fig. 7: Compare the fast idle speed to the graph ...

  1. If necessary, adjust by turning the fast idle adjusting screw.
  2.  



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Fig. Fig. 8: ... if necessary, turn the adjusting screw

If it is not possible to bring the fast idle speed within specification, it may be necessary to replace the left carburetor.

  1. Stop the engine and connect both coolant hoses.
  2.  
  3. Start the engine and allow it to reach normal operating temperature. Check the position of the fast idle lever. If the lever is seated against the cam, replace the left carburetor.
  4.  



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Fig. Fig. 9: If the lever is seated against the cam, replace the left carburetor

Float Level
ACCORD

See Figures 10 and 11

With the vehicle on level ground and at normal operating temperature, check the primary and secondary fuel level inspection windows on the side of the carburetor. Snap the throttle from idle to 3000 rpm several times, then allow the engine to idle. If the fuel level is not touching the indicator, adjust it by turning the screws which are located in recessed bosses above the inspection windows.



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Fig. Fig. 10: Check the fuel level in the inspection window



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Fig. Fig. 11: Turn the adjusting screw in small increments until the proper level is reached

Do not turn the adjusting screws more than1/8turn every 15 seconds.

When the correct fuel level is achieved in the window(s), put a dab of paint on the adjusting screws to lock their position.

PRELUDE

See Figure 12

With the carburetors and float chambers removed, hold the assembly so that the float chamber surface is inclined about 30 degrees from vertical. Use a float level gauge (Honda tool 07401-0010000 or equivalent) to measure the level with the float tip lightly contacting the needle valve. Correct measurement is 0.56-0.64 in. (14.2-16.2mm). Adjust the floats as needed.



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Fig. Fig. 12: Checking the float level on Preludes requires the removal of the carburetors and float chambers

Synchronization

Prelude dual carburetors must operate in synchronization to provide the same amount of air through each carburetor. The carburetors are synchronized at assembly and generally do not require resetting through the life of the car. However, if the carburetors have been removed and disassembled, they must be resynchronized.

1984-87 PRELUDE

See Figures 13 and 14

  1. Remove the air cleaner cover and filter.
  2.  
  3. Remove the air intake screens and air intake flanges.
  4.  
  5. Install synchronization adapters (Honda tool 07504-SB00000 or equivalent) to each carburetor intake; tighten the nuts only to 42 inch lbs. (5 Nm).
  6.  



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Fig. Fig. 13: Use of the synchronizers requires the use of adaptors

  1. Connect a tachometer and start the engine. Allow the engine to warm up fully until the cooling fans come on at least once.
  2.  
  3. Use a carburetor synchronization tool to measure the flow rate through both adapters. If the flow rates are identical, shut the engine off, remove the adapters and reassemble the air cleaner. The test is complete.
  4.  
  5. If the air flow rates are not identical, loosen the adjusting screw lock nut and adjust as needed. The adjusting screw only affects the right carburetor, so use the value from the left one as the baseline. Turn the adjusting screw clockwise to decrease airflow; counterclockwise to increase airflow. If the airflow cannot be balanced, inspect for air leaks around the carburetor or carbon build-up on the throttle plate.
  6.  



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Fig. Fig. 14: The synchronization screw is located on the throttle linkage-1984-87 models

  1. Tighten the adjusting screw locknut. Recheck the flow rates.
  2.  
  3. Shut the engine off. Remove the synchronizer and adapters. Install the air intake flanges and screens.
  4.  
  5. Reassemble the air filter and cover.
  6.  

1988-90 PRELUDE

See Figures 15 and 16

  1. Disconnect the red braided hose (marked PURGE) from the charcoal canister. Connect a vacuum gauge to the hose.
  2.  



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Fig. Fig. 15: Connect a vacuum gauge to the PURGE hose

  1. Connect a tachometer and start the engine. Allow the engine to run until it reaches normal operating temperature; the cooling fan should cycle on at least once.
  2.  
  3. Turn the idle speed adjusting screw until the engine speed is 3000 rpm. Note the reading on the gauge.
  4.  
  5. While the engine speed is at 3000 rpm, pinch the smooth red vacuum hose under the choke housing and note the change, if any, in the gauge reading.
  6.  
  7. If there was no change on the gauge, the carburetors are properly synchronized.
  8.  
  9. If the reading changed when the hose was pinched, adjust the synchronization screw until the readings are the same.
  10.  



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Fig. Fig. 16: If necessary, adjust using the synchronization screw-1988-90 models

  1. Remove the vacuum gauge and connect the PURGE hose to the canister. Remove the tachometer.
  2.  
  3. Reset the idle speed.
  4.  

REMOVAL & INSTALLATION



Accord

See Figures 17, 18, 19, 20, 21, 22, 23 and 24

  1. Disconnect the negative battery cable.
  2.  
  3. Remove the air cleaner cover.
  4.  
  5. Disconnect the fresh air and hot air hoses from the air cleaner.
  6.  
  7. Disconnect the vacuum lines from the air cleaner and mark their positions for proper reassembly. Disconnect the breather hose from the valve cover.
  8.  
  9. Remove the air cleaner mounting nuts and the air cleaner.
  10.  



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Fig. Fig. 17: Remove the air cleaner mounting nuts ...



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Fig. Fig. 18: ... then remove the air cleaner from the engine

  1. Disconnect the vacuum lines and electrical connectors from the carburetor and mark their positions for proper reassembly.
  2.  



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Fig. Fig. 19: On most models, the vacuum hoses are labeled from the factory

  1. Disconnect the throttle cable. Disconnect the throttle control cable (automatic transaxles) and/or cruise control cable if so equipped.
  2.  



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Fig. Fig. 20: Loosen the locknut, then disconnect the throttle cable from the linkage

  1. Disconnect and plug the fuel lines.
  2.  
  3. Remove the carburetor mounting nuts. Lift the carburetor off the mounting studs.
  4.  



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Fig. Fig. 21: An extension is useful for removing the mounting nuts



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Fig. Fig. 22: Lift the carburetor off the mounting studs

  1. If equipped, remove the electrically heated Early Fuel Evaporation (EFE) insulator.
  2.  



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Fig. Fig. 23: If equipped, remove the electrically heated Early Fuel Evaporation (EFE) insulator

  1. Plug the holes in the intake manifold with rags or a paper towel. Remove any old gasket material.
  2.  



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Fig. Fig. 24: Plug the holes in the intake manifold with rags or a paper towel. Remove any old gasket material

To install:
  1. Remove the rags or paper towels from the intake manifold.
  2.  
  3. Position the EFE insulator on the intake manifold.
  4.  
  5. Reinstall the carburetor on the insulator. Take care to keep debris from falling onto the EFE screen. Tighten the carburetor mounting nuts to 17 ft. lbs. (24 Nm).
  6.  
  7. Connect the fuel lines and secure the clamps.
  8.  
  9. Connect the cruise control and/or throttle control cables if they were removed. Connect and adjust the throttle cable.
  10.  
  11. Reinstall the vacuum lines to their correct ports. Double check the installation.
  12.  
  13. Engage the electrical connectors.
  14.  
  15. Install the air cleaner. Connect the fresh and hot air hoses. Connect the breather hose(s) and vacuum lines to the air cleaner as necessary.
  16.  
  17. Connect the negative battery cable. Start the engine and perform any carburetor adjustments as necessary.
  18.  

Prelude

See Figure 25

  1. Disconnect the negative battery cable.
  2.  
  3. Disconnect the fresh air intake duct and the hot air intake hose from the air cleaner.
  4.  
  5. Disconnect the vacuum hose to the hot air intake control diaphragm.
  6.  
  7. Remove the air cleaner cover and the filter element.
  8.  
  9. Disconnect the breather hose from the valve cover.
  10.  
  11. Carefully label and disconnect the vacuum hoses at the base of the air cleaner.
  12.  



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Fig. Fig. 25: Carefully label and disconnect the vacuum hoses; they are easily confused

  1. Unplug the electrical connectors at the top of the air cleaner base.
  2.  
  3. Remove the 10mm nuts under the air cleaner base.
  4.  
  5. Remove the 4 nuts, air screens and their flanges.
  6.  
  7. Remove the air cleaner base.
  8.  
  9. Carefully label, then disconnect, the vacuum hose connections running to the carburetor assembly.
  10.  
  11. Disconnect the throttle cable.
  12.  
  13. Disconnect the vacuum hoses at the vacuum tube manifold.
  14.  
  15. Drain the coolant and remove the coolant hoses at the thermowax valve.
  16.  
  17. Disconnect the vent hose running from the charcoal canister to the air vent cut-off solenoid.
  18.  
  19. Disconnect the canister purge hose at the vacuum manifold.
  20.  
  21. Unplug the carburetor wiring and the connector to the choke heater.
  22.  
  23. Remove the main fuel hose from the right side of the vacuum manifold.
  24.  
  25. Loosen the insulator bands and remove the carburetors as a unit with the vacuum manifold attached.
  26.  

To install:
  1. Place the carburetors in position. Make certain they are fully seated and tight in the insulators. Install the retaining bands.
  2.  
  3. Engage the carburetor wiring and the connector to the choke heater.
  4.  
  5. Install the main fuel hose to the right side of the vacuum manifold.
  6.  
  7. Connect the charcoal canister purge hose at the vacuum manifold.
  8.  
  9. Connect the charcoal canister vent hose.
  10.  
  11. Connect the coolant hoses at the thermowax valve.
  12.  
  13. Connect the vacuum hoses to the vacuum manifold.
  14.  
  15. Install the throttle cable.
  16.  
  17. Connect the vacuum lines at the carburetor.
  18.  
  19. Install the air cleaner base.
  20.  
  21. Install the air screens and flanges.
  22.  
  23. Install the 10mm bolts under the air cleaner base.
  24.  
  25. Attach the connectors at the top of the air cleaner base.
  26.  
  27. Connect the vacuum hoses to the air cleaner base.
  28.  
  29. Connect the breather hose to the valve cover.
  30.  
  31. Install the air cleaner housing, filter element and cover. Connect the vacuum hoses and air ducting.
  32.  

OVERHAUL




CAUTION
Carburetor cleaner is a highly caustic liquid; wear eye protection whenever spray or liquid cleaner is in use or when using compressed air. Immediately remove cleaner from any painted surfaces on the car.

Specific directions and specifications for carburetor overhaul are usually contained in the rebuilding kit.

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 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 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 plastic and plastic 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 or 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. Wear may allow air leakage, which could adversely affect starting and idling.
  6.  
  7. Inspect the idle mixture adjusting needles for burrs or grooves. Any such condition requires replacement of the needle, since you will not be able to obtain a satisfactory idle.
  8.  
  9. Check the bowl cover for warped surfaces with a straightedge.
  10.  
  11. After the carburetor is assembled, check the choke valve for freedom of operation.
  12.  

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 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
 
All diaphragms
 
Spring for the pump diaphragmMajor Repair Kits
 
All jets and gaskets
 
All diaphragms
 
Float needle valve
 
Pump ball valve
 
Float
 
Some cover hold-down screws and washers
 

Gasket kits contain all gaskets.

After cleaning and checking all components, reassemble the carburetor, using new parts and referring to the exploded view supplied in the kit. When reassembling, make sure that all screws and jets are tight in their seats, but do not overtighten, as the tips will be distorted. Tighten all screws gradually, in rotation. Always use new gaskets. Be sure to adjust the float level when reassembling.

 
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