Carburetor - Rochester e4mc/e4me Buick Electra Estate Wagon

COMPONENT TESTING

Note. Specific component testing information not available. Refer to any tests performed during REMOVAL & INSTALLATION or OVERHAUL procedures

APPLICATION

This carburetor is used on both General Motors and Chrysler Corp. vehicles. However, some of the information in this article is specific to the Chrysler Corp. models, where noted .

CARBURETOR APPLICATIONS

ROCHESTER CARBURETOR APPLICATIONS

IDENTIFICATION

The Rochester E4MC and E4ME carburetor numbers are stamped vertically on the float bowl, near secondary throttle. If float bowl is replaced, follow manufacturer's instructions contained in service package to transfer part number to new float bowl. Some models have machined pump wells to reduce the pump well taper.

The E4MC and E4ME Quadrajet carburetors are used nationwide with the Computer Command Control (CCC) system. The first letter "E" indicates the carburetor is a part of the CCC system. The final letter, if "E", indicates the carburetor is equipped with an electric choke; if "C", a hot air choke.

Carburetor Identification Label Transfer original part number from old float bowl if new bowl is installed. Scheme 1

DESCRIPTION

The E4MC and E4ME carburetors are of a 2-stage, downdraft design. The secondary circuit is composed of 2 large throttle bores, using the air valve principle, in which fuel is metered in direct proportion to the amount of air passing through the secondary throttle bores. A baffle is attached to the secondary side of the air horn, above the main well bleed tubes. This deflects incoming air to improve secondary nozzle operation on heavy acceleration.

The E4MC carburetor uses an air heated choke assembly; the E4ME, an electrically-actuated choke assembly. All E4MC and most E4ME models have 2 vacuum break diaphragm assemblies, primary and secondary, while some E4ME models have only the primary vacuum break assembly.

Chrysler Corp. vehicles use the Electronic Spark Control System (ESC). All carburetors are equipped with an electrically-actuated mixture control solenoid mounted in the float bowl. For all applications, fuel metering is controlled by stepped metering rods that operate in removable jets.

All models include tamper-resistant factory settings of the mixture control solenoid rich limit stop and lean mixture screw, idle air bleed valve, TPS, ILC, ISS and idle mixture screws. DO NOT adjust these except during major overhaul or replacement of air horn, float bowl or throttle body. Both electric and hot air chokes have riveted covers which must not be removed except for major overhaul. Chrysler Corp. engines use an Idle Speed Solenoid (ISS) for controlling idle speed.

ELECTRIC CHOKE

Note. This test should be performed when air temperature is 60-80°F (15-27°C).

1. Allow choke to cool to permit full closing of choke valve when throttle is opened slightly. Start engine and time the interval required for choke valve to reach full open position. If choke valve does not fully open within 3-1/2 minutes, proceed with test.
2. With engine running, check voltage at choke heater connection. If voltage is about 12-15 volts, replace electric choke unit. If voltage is low or zero, check all wires and connections and repair as required. Power for choke unit is through the oil pressure switch. Ensure switch circuitry is good.
3. If procedure in step 2) does not correct the problem, replace oil pressure switch.

HOT AIR CHOKE

1. Start and warm engine to normal operating temperature. Ensure choke valve fully opens. If valve does not fully open, check choke housing and hot air inlet to determine if sufficient heat is reaching choke coil.
2. If choke housing and/or hot air inlet are cool, check for loss of vacuum to choke housing, restricted heat inlet in choke housing, restricted hot air inlet pipe or hose and restricted manifold choke heat stove passages. Repair or replace as required.

Scheme 2

1. Using a "T" fitting, connect a vacuum gauge in vacuum line from valve to ILC. Connect a vacuum pump to port 1 of valve. Apply 17.8 in. Hg vacuum to port 1 and observe gauge. Gauge should read 16.9 in. Hg vacuum within 6-9 seconds. (Scheme 2) (Scheme 2): Location of Differential Vacuum Delay Valve Ports Identify ports for testing procedure.
2. Remove vacuum gauge and "T" fitting. Connect vacuum pump to port 2 and leave port 1 open. Air should flow through valve when.5 in. Hg vacuum is applied.

ADJUSTMENTS

Note. For all on-vehicle adjustments not covered in this article, see appropriate TUNE-UP article.

ANGLE GAUGE ADJUSTMENT TOOL

Manufacturer recommends that some carburetor adjustments be performed using Choke Valve Angle Gauge (J-26701). While preparations and actual adjustment may vary with each individual adjustment, the procedure for using the angle gauge to check the choke valve angle remains the same. Use the following procedure to perform adjustments requiring the use of the choke valve angle gauge.

Choke Valve Angle Gauge This gauge must be used to perform some adjustments. Scheme 3

1. With choke valve closed, place angle gauge magnet squarely on choke valve. Rotate degree scale on angle gauge so that 0° mark is opposite pointer.
2. Rotate leveling bubble on angle gauge until it is centered. Rotate degree scale until specified degree mark is opposite pointer.
3. Place gauge on throttle blade as specified in carburetor adjustment procedures. If bubble is centered, adjustment is correct. If not, adjust carburetor as outlined.

FLOAT LEVEL (WET SETTING)

Note. This is an on-vehicle adjustment.

Scheme 4

1. With engine running at idle and choke valve wide open, carefully insert float gauge into vent slot or vent hole (next to air cleaner mounting stud) in air horn. Allow gauge to float freely. (Scheme 4) NOTE: Pressing down on float gauge could result in float damage or carburetor flooding. (Scheme 4): Wet Float Level Adjustment Allow float gauge to float freely.
2. With gauge floating freely, observe mark on gauge which aligns with top of casting (at eye level). Reading should be within 2/32" (1.58 mm) of specified float level. Incorrect fuel pressure will affect fuel level.
3. If reading is not within 2/32" (1.58 mm) of specified float level, remove carburetor. Remove air horn and perform Float Level (Dry Setting) adjustment.

Dry Float Level Adjustment. Scheme 5

1. Remove air horn and gasket. Remove solenoid plunger, metering rods and float bowl insert. If necessary, remove solenoid lean mixture adjusting screw, making a record of the number of turns it takes to lightly bottom screw, using Solenoid Mixture Adjusting Tool (J-28696-10 or BT-7928).
2. Attach Gauge (J-34817-1 or BT-8227A-1) to float bowl. Place Weight (J-34817-3 or BT-8227A-1) in base with contact pin resting on outer edge of float lever.
3. Using Gauge (J-9789-90 or BT-8037), measure distance from top of casting to top of float, approximately 3/16" (4.763 mm) from large end of float.
4. If more than 2/32" (1.58 mm) from specification, use tool to bend lever up or down. (Scheme 5)
5. Remove bending tool and measure, repeating until within specification. Reassemble carburetor and install all fuel lines and vacuum tubes.

SOLENOID LEAN MIXTURE SCREW (BENCH ADJUSTMENT)

Note. This is a preliminary adjustment only. It is required to ensure that lean mixture screw is set close to specifications prior to final adjustment. Final adjustment must be made with carburetor installed and engine running. See appropriate TUNE-UP article.

Solenoid Lean Mixture Screw Bench Adjustment Lean mixture screw should be installed with first 6 threads engaged in float bowl. Scheme 6

1. Install plastic aneroid cavity insert beneath mixture control solenoid connector in float bowl, if used. Ensure insert is installed with inset aligned with recess of bowl cavity and seated flush with bowl casting surface. Tang on upper lip of insert goes in deep slot of bowl closest to fuel inlet nut.
2. Install mixture control solenoid screw tension spring between raised bosses next to float hanger pin. Install a new rubber gasket on top of solenoid connector. Install Mixture Control Solenoid Gauge Tool (J-33815-1 or BT-8253-A) over throttle lever side metering jet guide.
3. Carefully install mixture control solenoid and connector in float chamber. Align pin on end of solenoid with hole in raised boss at bottom of bowl. Align connector wires to fit in slot in bowl or plastic insert, if used.
4. Install solenoid lean mixture screw through solenoid rich limit stop bracket, and position plunger so that it slides freely on the stop bracket and through tension spring in float bowl.
5. Align solenoid plunger into solenoid body. Hand thread solenoid adjusting screw to ensure proper installation.
6. Hold solenoid plunger against solenoid stop. Using Lean Mixture Screwdriver (J-28696-10 or BT7928), slowly turn lean mixture screw clockwise until solenoid plunger just contacts gauging tool. (Scheme 6)
7. Adjustment is correct when solenoid plunger is contacting BOTH the solenoid stop and gauging tool. Remove solenoid plunger and gauging tool.

SOLENOID RICH MIXTURE STOP SCREW (BENCH ADJUSTMENT)

Note. This is a preliminary adjustment only. It is required to ensure that rich mixture stop screw is set close to specifications prior to final adjustment. Most General Motors models use a rich limit stop bracket and there is no adjustment. If equipped with an adjustment screw, final adjustment must be made with carburetor installed and engine running. See appropriate TUNE-UP article.

Solenoid Rich Mixture Stop Screw Bench Adjustment Air horn must be properly installed prior to adjustment. Scheme 7

1. With solenoid lean mixture screw properly set and air horn installed, insert plastic float gauge in vertical "D" shaped vent hole in air horn casting.
2. With float gauge installed, read mark on gauge that lines up with top of air horn casting at eye level. Record reading. Lightly depress float gauge and again read mark on gauge that lines up with top of casting. Record reading.
3. Subtract the 2 readings taken in step 2). This difference is the total solenoid travel. Using a "double D" wrench, turn rich mixture stop screw until total solenoid travel (difference between readings) is 4/32" (3.17 mm). (Scheme 7)
4. After adjustment, install lean mixture screw plug and rich mixture stop screw plug. Plugs must be installed to seal settings and to prevent fuel vapor loss. (Scheme 8)

Installing Lean Mixture Screw Plug & Rich Mixture Stop Screw Plug Plugs seal settings and prevent loss of fuel vapor. Scheme 8

IDLE MIXTURE (BENCH ADJUSTMENT)

Note. This is a preliminary adjustment only. It is required to ensure that mixture screws and idle air bleed valve are set close to specifications prior to final adjustment. Final adjustment must be made with carburetor installed and engine running. See appropriate TUNE-UP article.

Idle Mixture Bench Adjustment Final adjustments must be performed with carburetor installed and engine running. Scheme 9

1. With concealment plugs removed, use compressed air to remove any metal chips. Lightly seat mixture screws. Back out specified number of turns. See «IDLE MIXTURE SCREW CHART»(/buick/electra-estate-wagon/1985-1985/remont/testing-diagnostics/#carburetor-rochester-e4mce4me). IDLE MIXTURE SCREW CHART (CHRYSLER MODELS ONLY) Application Mixture Screw Preset (Turns) 17085407, 411 (1) 4 (1) Final adjustment performed on-vehicle.
2. Remove concealment plug. Remove air bleed valve. Discard "O" rings from valve. The air bleed valve is serviced as a complete assembly only.
3. Lightly coat "O" rings with automatic transmission fluid and install on air bleed valve. Install air bleed valve in air horn, ensuring proper thread engagement.
4. To adjust idle air bleed valve, insert Air Bleed Valve Gauging Tool (J-33815-2 or BT-8253-B) in throttle side "D" shaped vent hole in air horn casting. Upper end of tool should be positioned over open cavity next to valve. (Scheme 9)
5. Hold the gauging tool down lightly so solenoid plunger is against solenoid stop. Adjust air bleed valve so gauging tool will pivot over and just contact top of valve. (Scheme 9)

ACCELERATOR PUMP ROD

No accelerator pump rod adjustment is required.

Scheme 10

1. Use 3/32" (2.38 mm) Allen wrench to loosen lock screw. Turn tension adjusting screw counterclockwise until air valve opens part way.
2. Turn tension adjusting screw clockwise until air valve just closes. Then turn adjusting screw clockwise specified number of turns. (Scheme 10) (Scheme 10): Air Valve Spring Adjustment Apply lithium base grease to lubricate contact area.
3. Hold adjusting screw and tighten lock screw. Apply lithium base grease to lubricate contact area.

CHOKE COIL LEVER

Note. Choke coil cover uses rivets in place of retaining screws. If necessary to remove choke coil cover, refer to DISASSEMBLY and REASSEMBLY procedures under OVERHAUL in this article.

Choke Coil Lever Adjustment Bend choke rod to adjust. Scheme 11

1. Remove retaining rivets. Remove choke cover and coil assembly from choke housing. (Scheme 11)
2. Position fast idle speed cam follower on high step of fast idle cam.
3. Push up (counterclockwise) on choke coil tang to close choke valve.
4. Insert.120" drill or plug gauge in hole provided in choke housing. Lower edge of choke lever inside housing should just touch drill or plug gauge.
5. To adjust, bend choke rod. (Scheme 11)

Note. Electric choke units do not use a gasket between choke cover and choke housing.

CHOKE ROD (FAST IDLE CAM)

Note. Choke coil lever adjustment must be correct before performing this adjustment. Fast idle speed adjustment must be performed using the Emission Control Tune-Up Decal with carburetor installed and vehicle running. Adjustment is performed with choke valve angle gauge. Refer to the ANGLE GAUGE ADJUSTMENT TOOL procedure at beginning of ADJUSTMENTS. DO NOT remove rivets and choke cover to perform this adjustment.

Choke Rod (Fast Idle Cam) Adjustment Bend tang on fast idle cam to adjust. Scheme 12

1. Attach rubber band to Green tang of intermediate choke shaft. Open throttle to allow choke valve to close. Set angle gauge onto choke valve and set to specified angle.
2. Place fast idle speed cam follower on second step of fast idle cam against shoulder of highest step. If cam follower does not contact cam, turn in fast idle speed screw additional turns. (Scheme 12)
3. To adjust, bend tang on fast idle cam until bubble of choke valve angle gauge is centered.

Front Vacuum Break Adjustment Turn vacuum break adjustment screw to adjust. Scheme 13

Note. Choke coil lever and choke rod (fast idle cam) adjustments must be correct before performing this adjustment. Adjustment is performed with choke valve angle gauge. See ANGLE GAUGE ADJUSTMENT TOOL procedure at beginning of ADJUSTMENTS. DO NOT remove rivets and choke cover to perform this adjustment.

1. Attach rubber band to Green tang of intermediate choke shaft. Open throttle to allow choke valve to close. Set angle gauge onto choke valve and set to specified angle.
2. Using an outside vacuum source of at least 18 in. Hg, fully retract primary (front) vacuum break diaphragm. If air valve rod restricts vacuum break plunger from retracting, bend rod to allow full plunger travel. Be sure leaf bucking spring is seated against lever, if equipped. (Scheme 13) NOTE: On models equipped with air bleed, remove rubber cover from filter and plug vacuum tube with a piece of tape. If bleed hole is in end of diaphragm, plug hole in end of diaphragm with a piece of tape. Remove tape after completing adjustment.
3. To adjust, turn vacuum break adjustment screw with vacuum still applied. Adjustment is correct when bubble of choke valve angle gauge is centered.

SECONDARY (REAR) VACUUM BREAK

Note. Choke coil lever and choke rod (fast idle cam) adjustments must be correct before performing this adjustment. Adjustment is performed with choke valve angle gauge. See procedure at beginning of Adjustments. DO NOT remove rivets and choke cover to perform this adjustment.

Secondary (Rear) Vacuum Break Adjustment Turn screw or bend vacuum break rod to adjust. Scheme 14

1. Attach rubber band to Green tang of intermediate choke shaft. Open throttle to allow choke valve to close. Set angle gauge onto choke valve and set to specified angle.
2. Using an outside vacuum source of at least 18 in. Hg, fully retract secondary (rear) vacuum break diaphragm. If air valve rod restricts vacuum break plunger from retracting, bend rod to allow full plunger travel. Be sure leaf bucking spring is compressed, if equipped. (Scheme 14) NOTE: On models equipped with air bleed, remove rubber cover from filter and plug vacuum tube with a piece of tape. If bleed hole is in end of diaphragm, plug hole in end of diaphragm with tape. On delay models with air bleed, plug end cover with an accelerator pump plunger cup. Remove tape or cup after completion of adjustment.
3. To adjust on models equipped with hex adjustment, use a 1/8" hex wrench to turn adjustment screw in rear cover of vacuum break with vacuum still applied. To adjust on models without hex adjustment, support rod at "S" and bend vacuum break rod with vacuum still applied. Adjustment is correct when bubble of choke valve angle gauge is centered.

Scheme 15

1. Using an outside vacuum source, at least 18 in. Hg, fully retract primary (front) vacuum break diaphragm. Plug purge bleed hole (if equipped) with masking tape. Hole is located in end of diaphragm. (Scheme 15) (Scheme 15): Air Valve Rod Adjustment - Front Air valve must be completely closed.
2. Ensure air valve is completely closed. Measure clearance between rod and end of slot in lever. Insert a.025" drill or plug gauge between rod and end of slot. (Scheme 15)
3. Bend rod at point shown to adjust gauge clearance to.025" with vacuum still applied. Remove tape and reconnect vacuum hose to diaphragm.

AUTOMATIC CHOKE

Note. Choke coil cover is retained in place with rivets. No adjustment is required. If necessary to remove choke coil cover, refer to Disassembly and Reassembly procedures in this article. Remove choke cover only if major overhaul is required or if choke cover requires replacement.

CHOKE UNLOADER

Note. Choke coil lever and choke rod (fast idle cam) adjustments must be correct before performing this adjustment. Adjustment is performed with choke valve angle gauge. See ANGLE GAUGE ADJUSTMENT TOOL procedure at beginning of ADJUSTMENTS. DO NOT remove rivets and choke cover to perform this adjustment.

Choke Unloader Adjustment Bend tang to adjust. Scheme 16

1. Attach rubber band to Green tang of intermediate choke shaft. Open throttle to allow choke valve to close. Set angle gauge onto choke valve and set to specified angle.
2. Hold secondary lockout lever away from pin. (Scheme 16) Hold throttle lever in wide open position.
3. To adjust, bend choke unloader tang of fast idle lever until bubble of choke valve angle gauge is centered. Remove gauge.

Scheme 17

1. Hold choke valve and throttle valves completely closed. (Scheme 17) (Scheme 17): Secondary Throttle Valve Lockout Adjustment
2. Measure secondary throttle valve lock-out specified side clearance between pin and lock-out lever.
3. Specified lock-out lever side clearance is.015" (.381 mm). To adjust, bend pin.

Lock-Out Lever Opening Clearance

1. Push down on tail of fast idle cam to open choke valve completely.
2. Measure secondary throttle valve lock-out specified opening clearance between end of pin and toe of lock-out lever.
3. Specified clearance is .015" (.381 mm), To adjust, file end of lock-out pin. Make sure all burrs are removed.

DISASSEMBLY

Note. Before performing any service on carburetor, place carburetor on a Holding Fixture (J-9789-118) to prevent damage to throttle valves.

Air Horn

1. Remove ILC, or ISS attaching screws, bracket and assembly. Remove upper choke lever from end of choke shaft by removing retaining screw. Rotate upper choke lever to remove choke rod from slot in lever.
2. Remove choke rod from lower lever inside float bowl casting. Remove rod by holding lower lever outward with small screwdriver and twisting rod counterclockwise.
3. Remove secondary metering rods by removing small screw in top of metering rod hanger. Lift up on metering rod hanger until secondary metering rods clear air horn. Metering rods may be disassembled from hanger by rotating ends out of holes in end of hanger.
4. Using a small drift punch, drive pump lever pivot pin (roll pin) inward until pin is against air cleaner locating boss on air horn casting. Disconnect pump rod from pump lever.
5. Remove vacuum hose from primary vacuum break unit and note location for reassembly reference. Remove 11 air horn-to-float bowl screws. Remove 2 countersunk screws located near venturi. CAUTION: Be careful when removing roll pin to avoid damage to pump lever bosses.
6. Remove secondary air baffle deflector (if equipped) from beneath 2 center air horn screws. Remove air horn from float bowl by lifting straight up. Air horn gasket should remain on float bowl. NOTE: Use care not to damage mixture control solenoid connector, TPS adjustment lever, and small tubes protruding from air horn. DO NOT attempt to remove small tubes.
7. Remove primary vacuum break diaphragm. Remove vacuum break from the air valve rod dashpot link, and dashpot link from air valve lever. Using fingers only, remove TPS plunger by pushing plunger up through air horn seal.
8. Remove TPS seal by inverting air horn and remove staking from around seal retainer with a small screwdriver. Remove and discard retainer and seal. Use care removing retainer and seal to prevent damage to air horn casting.
9. Using a punch and small hammer, remove and discard Lean Mixture Screw plug. Further disassembly of air horn assembly is not required for cleaning purposes. Choke valve and choke valve screws, air valve and air valve shaft should not be removed. Instructions for replacing the air valve closing spring and plastic cam are included in service kit. NOTE: It will be necessary to remove air bleed valve before air horn can be immersed in carburetor cleaner.
10. If necessary to replace idle air bleed valve or disassemble air horn for immersion in carburetor cleaner, cover internal bowl vents and air inlets to bleed valve with tape. Drill off rivet heads of bleed valve cover with a 7/64" drill. Drive remainder of rivet out of tower with drift and small hammer.
11. Lift out cover over valve and remove remaining rivet pieces from inside tower. Turn valve counterclockwise and remove from air horn. Remove and discard "O" ring seals from air bleed valve. Air bleed valve is serviced as a complete assembly only.

Float Bowl

1. Remove air horn gasket by lifting off of dowel locating pins. Discard gasket. Remove accelerator pump plunger and return spring from pump well.
2. Using Mixture Solenoid Mixture Tool (J-28696-10 or BT-7928), loosen mixture solenoid adjusting screw. Remove solenoid adjusting screw, solenoid plunger, and plunger stop bracket (rich limit) as an assembly.
3. Remove solenoid connector attaching screw. DO NOT remove plunger return spring or connector wires from solenoid as it is serviced as a complete assembly.
4. Remove plastic insert from over mixture control solenoid. Carefully lift out each metering rod from guide. Ensure the return spring is removed with each rod.
5. Remove and discard rubber gasket from top of solenoid connector. Remove solenoid adjusting screw tension spring from float bowl. Remove float, needle and seat by pulling up on retaining pin. Using Wrench (J-22769 or BT-3006M) remove needle seat and remove gasket.
6. Remove large mixture control solenoid tension spring from boss on bottom of float bowl located between metering jet guides. Remove mixture control solenoid.
7. Remove staking holding TPS in bowl. To do so, protect gasket surface by laying a flat piece of metal across casting.
8. Using a small screwdriver, lightly depress and hold TPS down against spring tension. Carefully remove staking from around TPS by prying upward with a small chisel against the metal piece (not bowl casting).
9. Push up from bottom on electrical connector and remove TPS and connector assembly from bowl. Use care not to damage sensor during removal. Remove spring from bottom of TPS well. Remove plastic filler block from float valve.
10. Using Wrench (J-28696-4 or BT-7928), carefully remove primary metering jets. Make sure return spring is removed with each rod. Remove return spring by sliding it off metering rod. DO NOT attempt to remove secondary metering jets.
11. Remove pump discharge check ball retainer. Invert bowl and catch discharge ball as it falls. Remove secondary air baffle, if replacement is necessary. Remove pump well fill slot baffle, only if necessary.
12. Remove hose from secondary (rear) vacuum break. Remove attaching screws and rotate assembly to remove diaphragm rod from slot in plunger.
13. Align a .159" (No. 21) drill on choke cover retaining rivets and drill only enough to remove rivet head. Using a drift and hammer, drive remainder of rivets out of choke housing. Remove 3 retainers, choke cover gasket (hot air type chokes) and choke cover from choke housing. NOTE: DO NOT remove baffle plate from beneath thermostatic coil on choke cover of hot air type chokes.
14. Remove retaining screw and washer from inside choke housing. Slide choke housing from float bowl. On hot air type chokes, remove plastic type seal from vacuum inlet boss of choke housing.
15. Remove secondary throttle valve lockout lever from float bowl. Remove lower choke lever from inside float bowl cavity by turning float bowl upside down. Remove coil lever retaining screw from end of intermediate choke shaft and remove lever.
16. Slide intermediate choke shaft from choke housing. Remove fast idle cam from intermediate choke shaft. On hot air type chokes, remove and discard cup seal inside choke housing shaft hole.
17. Remove intermediate choke shaft cup seal from float bowl insert. DO NOT remove insert. Invert float bowl to remove lower choke lever from bowl cavity. Remove fuel inlet nut, gasket and filter. Remove 3 throttle body-to-float bowl screws and throttle body.

Throttle Body

1. Remove accelerator pump rod from throttle lever by rotating rod until tang aligns with slot in lever. NOTE: Further disassembly of throttle body is not required for normal cleaning. Throttle valve screws are permanently staked in position. Throttle body is serviced as complete assembly. DO NOT remove mixture screw plugs unless diagnosis indicates the carburetor is cause of poor engine performance or idle mixture needles or throttle body must be replaced. If necessary to remove plugs, continue as follows
2. Turn throttle body over, and position on a holding fixture with manifold side up. Make 2 parallel cuts in throttle body using small hacksaw, cutting on each side of idle mixture needle plug. Cuts should reach down to steel plug, but no more than 1/8" beyond locator points. Distance between saw marks will depend upon size of punch used.
3. Place a flat punch at a point near ends of saw marks. Hold punch at 45° angle and drive it into throttle body until casting breaks away, exposing steel plug.
4. Hold punch vertically and drive it into steel plug. Then hold punch at 45° angle and drive plug out of casting. Repeat process for remaining mixture needle. Using Wrench (J-29030-B or BT-7610B), remove idle mixture needles. Refer to Idle Mixture (Bench Adjustment) procedure in this article.

Note. Hardened steel plug will shatter. It is not necessary to remove plug completely. Remove just enough pieces to allow idle mixture adjusting tool to be used to remove mixture screws and springs. Idle mixture screw head has a "double-D" configuration and can also be removed using a piece of 7/32" copper tubing that has been partially flattened.

CLEANING & INSPECTION

1. Use a regular carburetor cleaning solution. Soak components long enough to thoroughly clean all surfaces and passages of foreign matter.
2. DO NOT soak any components containing rubber, leather or plastic. Particularly DO NOT soak air horn with idle air bleed valve installed, electric choke, ISS, ILC, TPS, thermostatic choke cover and coil, vacuum break diaphragms, pump plunger and other such parts.
3. Remove any residue after cleaning by rinsing components in a suitable solvent.
4. Blow out passages with dry compressed air.

REASSEMBLY

Note. Use new gaskets and seals. Make sure that new gaskets fit correctly and that all holes and slots are punched through and correctly located.

Scheme 18

1. Reassemble carburetor in reverse order of disassembly. The intermediate choke shaft lever and fast idle cam are assembled correctly when tang on lever is beneath fast idle cam.
2. When installing float and retaining pin, make sure open end of float retaining pin faces accelerator pump well. (Scheme 18): Exploded View of Rochester E4MC & E4ME Carburetor
3. When installing fuel inlet valve, hook pull clip over edge of flat on float arm. DO NOT hook clip in holes in float arm.
4. When installing mixture control solenoid, make sure pin on end of solenoid aligns with hole in raised boss at bottom of float bowl.
5. Install, adjust and plug all screws to restore tamper-resistant design. NOTE: If choke coil cover was removed, it will be necessary to install service rivet retaining kit. Before installing cover, place fast idle screw on high step of fast idle cam. Align notch in cover with raised boss on housing cover flange and install rivets.
6. Place fast idle screw on high step of fast idle cam. Install choke coil cover if removed, aligning notch in cover with tab on cover retainer (supplied in service kit). Be sure coil tang engages pick-up lever. Install blind rivets. NOTE: On E4ME models, ground contact for electric choke is provided by metal plate located at rear of choke cover assembly. DO NOT install choke cover gasket between electric choke and housing.
7. Install air horn screws and tighten evenly, securely and in sequence (Scheme 19)

Air Horn Screw Tightening Sequence Screws 1 and 2 are countersunk next to venturi. Scheme 19

CARBURETOR ADJUSTMENT SPECIFICATIONS (E4MC)

CARBURETOR ADJUSTMENT SPECIFICATIONS (E4ME)

See also:
• IDLE MIXTURE SCREW CHART
• ANGLE GAUGE ADJUSTMENT TOOL