Carburetor - Mikuni 2-bbl Dodge Caravan I

COMPONENT TESTING

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

APPLICATION

CHRYSLER MOTORS (MIKUNI) CARBURETOR NO.

IDENTIFICATION

Carburetor identification is located on a metal tag attached to carburetor.

DESCRIPTION

The 2.6L engine uses a 2-barrel carburetor of standard downdraft design. Six basic systems are used: fuel inlet, primary metering, secondary metering, automatic choke, enrichment, and fuel cut-off.

Other features include: diaphragm accelerator pump, bowl vent, fuel cut-off solenoid and air switching valve (ASV).

In addition, California and High Altitude models include a sub-EGR valve, Coasting Air Valve (CAV), Jet Air Control Valve JACV), and High Altitude Compensating (HAC) system.

The main carburetor body is made of plastic resin to reduce heat transfer to the float bowl. The automatic choke is a thermo-wax pellet type controlled by engine coolant.

ADJUSTMENT

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

FLOAT LEVEL

Invert air horn assembly (without gasket). Allow weight of float assembly to seat inlet valve. (Scheme 22) Distance from bottom edge of float to surface of air horn should be.88" (22.4mm). If not, adjust by adding or removing shims under inlet needle seat.

Note. Distance from bottom edge of float to surface of air horn has been revised as per TSB # 14-04-88 dated April 18, 1988.

Note. All other adjustments are factory made and should not be changed in service.

Float Level Adjustment Make measurement without gasket. Courtesy of Chrysler Motors. Scheme 22

Scheme 23

1. Remove water hoses from choke assembly. Drill out staked portion or grind off heads of choke cover retaining screws. Using a small hammer and pointed punch, tap remaining choke cover screw counterclockwise to remove. Note position of scribe marks on choke pinion plate relative to punch mark. (Scheme 23)
2. Remove "E" clip from throttle opener link, then remove screws and throttle opener. Disconnect fuel cut-off solenoid ground wire and remove solenoid. Disconnect throttle return and damper springs. Remove "E" clips and choke unloader link.
3. Disconnect vacuum hose and vacuum chamber link. Remove screws and vacuum chamber. Disconnect throttle operating rod link. remove 6 air horn screws and lift air horn off carburetor body.
4. Remove vacuum hose connector retaining screws (2), then remove hoses and connector. Slide float pivot pin out. Remove float and inlet needle. Remove and discard air horn gasket. Remove screw and retainer, and then remove needle seat and screen assembly. Be sure not to lose shim from under needle seat.
5. Remove primary and secondary venturi retainers, venturi, and "O" rings. Mark each venturi for reassembly reference. Remove primary and secondary main jets from pedestals and note jet numbers for correct installation. Remove screws and pedestals.
6. Remove bowl vent solenoid screws. Separate solenoid from owl vent and remove spring. Remove bowl vent, "O" ring, and seal rom air horn. Discard "O" ring and seal. On California and High ltitude models, remove 3 coasting air valve screws, cover, retainer leeve, spring, spring retainer, diaphragm and seal.
7. On all models, remove 3 enrichment valve screws, valve cover, valve, gasket, and jet. Remove 2 air switching valve screws nd valve assembly. Take out spring retainer sleeve, spring, etainer, and diaphragm seal. Remove screw, lock plate, and primary et set. Repeat procedure for secondary jet set.
8. From top of air horn, remove primary and secondary air bleed jets. Note locations of jets for proper installation. Invert air horn to remove pump weight, check ball, and hex nut. Remove 4 accelerator pump screws, cover, diaphragm, spring, pump body, check ball, and gasket.
9. On California and High Altitude models, remove 3 jet air control valve screws, cover, spring, spring retainer, and diaphragm. remove "E" clip from sub-EGR valve lever. Carefully slide pin from sub-EGR valve. Spring tension on lever is caused by steel ball and spring in sub-EGR valve. Use care when removing pin so as not to lose spring and check ball. Remove valve and boot seal.

Scheme 24

CLEANING & INSPECTION

1. DO NOT immerse plastic or rubber parts in solvent. DO NOT soak solenoids or choke assembly in any liquid.
2. Blow out all passages with compressed air. DO NOT use wire or drill bit to clean calibrated orifices or jets.
3. DO NOT use compressed air to blow out any diaphragm fittings if diaphragm is installed.
4. Inspect all parts for cracks, burrs, or pitting. Replace any damaged parts and all "O" rings, seals, and gaskets.
5. If recommended by solvent manufacturer, use hot water to rinse parts after cleaning. Blow dry with compressed air.

Scheme 25

REASSEMBLY

1. To assemble, reverse disassembly procedure. Install sub-EGR valve and verify proper operation. Install jet air control valve and tighten screws.
2. When installing primary and secondary air bleed jets, and primary and secondary main jets, largest numbered jet should be installed on secondary side.
3. When throttle body is completely assembled, and before installing on main body, check float level. See «FLOAT LEVEL»(/dodge/caravan/i-1984-1990/remont/testing-diagnostics/#carburetor-mikuni-2-bbl__float-level) adjustment procedure. Install choke cover and stake 4 screws in position. Tighten last screw with small hammer and pointed punch.
4. Check alignment of punch mark with scribed line of pinion plate and punch mark of cam lever with Green paint mark of pinion plate gear. (Scheme 23)and (Scheme 26).

Scheme 26

See also:
• FLOAT LEVEL