GM Blazer/Jimmy/Typhoon/Bravada 1983-1993 Repair Guide

2SE and E2SE Carburetor

Imprimir

The 2SE and E2SE carburetors are found on the 2.0L engine and early models of the 2.8L engines covered by this guide.

ADJUSTMENTS



Float Level

See Figure 1

  1. With the engine COLD, remove the top of the carburetor.
  2.  
  3. While holding a finger lightly (but firmly) on the float retainer, press down lightly on the float tab to seat the needle valve.
  4.  
  5. Measure the distance between the float bowl gasket surface and the point on the float farthest from the needle valve.
  6.  
  7. If the measurement is not correct, remove the float and bend the tab.
  8.  

Pump
  1. With the throttle plate in the closed position and the fast idle screw off the steps of the fast idle cam, measure the distance from the air horn casting to the top of the pump stem.
  2.  
  3. To adjust, remove the retaining screw, the washer and the pump lever. Bend the end of the lever to correct the stem height. DO NOT twist the lever or bend it sideways.
  4.  
  5. Install the lever, washer and screw, then check the adjustment. When correct, open and close the throttle a few times to check the linkage movement and alignment.
  6.  

Fast Idle
  1. Set the ignition timing and curb idle speed, then disconnect and plug the hoses as directed on the emission control decal.
  2.  
  3. Position the fast idle screw on the highest step of the fast idle cam.
  4.  
  5. Start the engine and adjust the engine speed to specification with the fast idle screw.
  6.  

Choke Coil Lever

See Figure 2

The following procedure requires the use of the Choke Valve Angle Gauge tool No. J-26701, BT-7704 or equivalent.

  1. Remove the three retaining screws, the choke cover and coil. On models with a riveted choke cover, drill out the three rivets, then remove the cover and the choke coil.
  2.  

A choke stat cover retainer kit is required for reassembly.

  1. Place the fast idle screw on the high step of the fast idle cam.
  2.  
  3. Close the choke plate by pushing in on the intermediate choke lever.
  4.  
  5. Insert a drill bit or plug gauge, of the specified size, into the hole in the choke housing. The choke lever in the housing should be up against the side of the gauge.
  6.  
  7. If the lever does not just touch the gauge, bend the intermediate choke rod to adjust.
  8.  

Fast Idle Cam (Choke Rod)

See Figures 3 and 4

The following procedure requires the use of the Choke Valve Angle Gauge tool No. J-26701, BT-7704 or equivalent.

  1. Adjust the choke coil lever and fast idle speed.
  2.  
  3. Rotate the degree scale until it is zeroed.
  4.  
  5. Close the choke and install the degree scale onto the choke plate. Center the leveling bubble.
  6.  
  7. Rotate the scale so that the specified degree is opposite the scale pointer.
  8.  
  9. Place the fast idle screw on the second step of the cam (against the high step). Close the choke by pushing in the intermediate lever.
  10.  



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Fig. Fig. 1: Adjusting the float level - 2.0L and 2.8L engines



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Fig. Fig. 2: Adjusting the choke coil lever - 2.0L and 2.8L engines



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Fig. Fig. 3: Adjusting the choke rod - 2.0L and 2.8L engines



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Fig. Fig. 4: Make sure the fast idle screw is properly positioned on the cam; the cam is not fully turned to the 2nd step here

  1. Push on the vacuum break lever, to open the choke, until the lever is against the rear tang on the choke lever.
  2.  
  3. Bend the fast idle cam rod at the U to adjust the angle to specifications.
  4.  

Air Valve Rod

See Figure 5

The following procedure requires the use of the Choke Valve Angle Gauge tool No. J-26701, BT-7704 or equivalent.

  1. Align the 0° mark with the pointer on an angle gauge.
  2.  
  3. Close the air valve and place a magnet on top of it.
  4.  
  5. Rotate the bubble until it is centered.
  6.  
  7. Rotate the degree scale until the specified degree mark is aligned with the pointer.
  8.  
  9. Seat the vacuum diaphragm using an external vacuum source.
  10.  
  11. On four cylinder models, plug the end cover. Unplug after adjustment.
  12.  
  13. Apply a light pressure to the air valve shaft in the direction to open the air valve until all the slack is removed between the air link and plunger slot.
  14.  
  15. Bend the air valve link until the bubble is centered.
  16.  

Primary Side Vacuum Break

See Figure 6

The following procedure requires the use of the Choke Valve Angle Gauge tool No. J-26701, BT-7704 or equivalent.

  1. Rotate the degree scale on the measuring gauge until the 0° mark is opposite the pointer.
  2.  

Prior to adjustment, remove the vacuum break from the carburetor. Place the bracket in a vise and, using the proper safety precautions, grind off the adjustment screw cap, then reinstall the vacuum break.

  1. Seat the choke vacuum diaphragm by applying an external vacuum source of over 5 in. Hg (127mm Hg) to the vacuum break.
  2.  

If the air valve rod is restricting the vacuum diaphragm from seating, it may be necessary to bend the air valve rod slightly to gain clearance. Make the air valve rod adjustment after the vacuum break adjustment.

  1. Read the angle gauge while lightly pushing on the intermediate choke lever so that the choke valve is toward the closed position.
  2.  
  3. Using a 1 / 8 in. (3mm) hex wrench, turn the screw in the rear cover until the bubble is centered. Apply a silicone sealant over the screw head to seal the setting.
  4.  



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Fig. Fig. 5: Adjusting the air valve rod - 2.0L and 2.8L engines



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Fig. Fig. 6: Adjusting the primary vacuum break - 2.0L and 2.8L engines

Electric Choke

This procedure is only for those carburetors with choke covers retained by screws. Riveted choke covers are preset and nonadjustable.

  1. Loosen the three retaining screws.
  2.  
  3. Place the fast idle screw on the high step of the cam.
  4.  
  5. Rotate the choke cover to align the cover mark with the specified housing mark.
  6.  

Secondary Vacuum Break

The following procedure requires the use of the Choke Valve Angle Gauge tool No. J-26701, BT-7704 or equivalent.

  1. Rotate the degree scale on the measuring gauge until the 0° mark is opposite the pointer.
  2.  

Prior to adjustment, remove the vacuum break from the carburetor. Place the bracket in the vise, and using the proper safety precautions, grind off the adjustment screw cap, then reinstall the vacuum break. Plug the end cover using an accelerator pump plunger cup or equivalent. Remove the cup after the adjustment.

  1. Seat the choke vacuum diaphragm by applying an external vacuum source of over 5 in. Hg (127 mm Hg) to the vacuum break.
  2.  

If the air valve rod is restricting the vacuum diaphragm from seating it may be necessary to bend the air valve rod slightly to gain clearance. Make an air valve rod adjustment after the vacuum break adjustment.

  1. Read the angle gauge while lightly pushing on the intermediate choke lever so that the choke valve is toward the closed position.
  2.  
  3. Using a 1 / 8 in. (3mm) hex wrench, turn the screw in the rear cover until the bubble is centered. Apply silicone sealant over the screw head to seal the setting.
  4.  

Choke Unloader

See Figure 7

  1. Follow Steps 1-4 of the Fast Idle Cam Adjustment.
  2.  
  3. If removed, install the choke cover and the coil, then align the housing marks with the cover marks, as specified.
  4.  
  5. Hold the primary throttle valve wide open.
  6.  
  7. If the engine is warm, push inward on the intermediate choke lever to close the choke valve.
  8.  
  9. Bend the unloader tang until the bubble is centered.
  10.  

Secondary Lockout

See Figure 8

  1. Place the choke in the wide open position by pushing outward on the intermediate choke lever.
  2.  
  3. Open the throttle valve until the end of the secondary actuating lever is opposite the toe of the lockout lever.
  4.  
  5. Gauge the clearance between the lockout lever and secondary lever, as specified.
  6.  
  7. To adjust, bend the lockout lever where it contacts the fast idle cam.
  8.  



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Fig. Fig. 7: Adjusting the choke unloader - 2.0L and 2.8L engines



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Fig. Fig. 8: Adjusting the secondary lockout - 2.0L and 2.8L engines

REMOVAL & INSTALLATION



See Figures 9, 10, 11, 12, 13, 14 and 15

2.0L Engine
  1. Disconnect the negative battery cable.
  2.  
  3. Remove the air cleaner and the gasket.
  4.  
  5. Disconnect the fuel pipe and all of the vacuum lines. Tag the vacuum lines to ensure proper installation.
  6.  
  7. Label and disengage all of the electrical connections.
  8.  
  9. If equipped with A/T, disconnect the downshift cable.
  10.  
  11. If equipped with cruise control, disconnect the linkage.
  12.  
  13. Remove the carburetor-to-intake manifold bolts and the carburetor, then discard the old mounting gasket.
  14.  

Be sure to cover the opening in the intake manifold to prevent debris, foreign material or even a mishandled bolt from entering the engine.

To install:

Before installing the carburetor, fill the float bowl with gasoline to reduce the battery strain and the possibility of backfiring when the engine is started again.

  1. Inspect the EFE heater for damage. Using a putty knife, clean the gasket mounting surfaces. Be sure that the throttle body and EFE mating surfaces are clean.
  2.  
  3. Install the carburetor using a new gasket, then secure using the carburetor-to-intake manifold bolts. Tighten the bolts, slowly and evenly.
  4.  
  5. If equipped with cruise control, connect the linkage.
  6.  
  7. If applicable, connect the downshift cable.
  8.  
  9. Engage all of the electrical connections, as tagged during removal.
  10.  
  11. Connect the fuel pipe and all of the vacuum lines, as noted during removal. If necessary, refer to the vacuum diagrams in Emission Controls of this guide.
  12.  
  13. Install the air cleaner and the gasket.
  14.  
  15. Connect the negative battery cable, then check and adjust idle speed, as necessary.
  16.  



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Fig. Fig. 9: Since the carburetor is located directly under the air cleaner, few other components must be removed for access



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Fig. Fig. 10: Vacuum lines should be tagged as they are disconnected to assure proper installation



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Fig. Fig. 11: Loosen and remove the carburetor retainers



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Fig. Fig. 12: A ratchet and extension can be handy in removing the retainers from the rear of the carburetor flange



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Fig. Fig. 13: With the retainers removed and all hoses/wiring disconnected, the carburetor can be lifted from the intake

2.8L Engine
  1. Disconnect the negative battery cable.
  2.  
  3. Remove the air cleaner assembly.
  4.  
  5. Disconnect the fuel and vacuum lines from the carburetor. Be sure to tag all vacuum lines to assure proper installation.
  6.  
  7. Disengage the electrical connectors from the carburetor.
  8.  
  9. Disconnect the linkage from the carburetor.
  10.  
  11. Remove the carburetor-to-intake manifold nuts and/or bolts, then remove the carburetor from the engine and discard the old gasket.
  12.  

Be sure to cover the opening in the intake manifold to prevent debris, foreign material or even a mishandled bolt from entering the engine.

To install:
  1. Using a putty knife, clean the gasket mounting surfaces.
  2.  
  3. Install the carburetor using a new gasket, then secure using the carburetor-to-intake manifold bolts. Tighten the nuts and/or bolts, slowly and evenly.
  4.  
  5. Connect the linkage to the carburetor.
  6.  
  7. Engage the electrical connectors to the carburetor.
  8.  
  9. Connect the fuel and vacuum lines to the carburetor. Make sure all vacuum lines are properly connected as noted during removal. If necessary, refer to the vacuum diagrams in Emission Controls of this guide.
  10.  
  11. Install the air cleaner assembly.
  12.  
  13. Connect the negative battery cable, then check and adjust idle speed, as necessary.
  14.  



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