Carburetor - Mikuni 2-bbl Dodge Aries I

COMPONENT TESTING

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

APPLICATION

CHRYSLER CORP. (MIKUNI) CARBURETOR NO. 2.6L ENGINE

IDENTIFICATION

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

DESCRIPTION

All 2.6L engines are equipped with a 2-barrel down draft carburetor designed for electronic fuel control and closed loop operation. The closed loop system provides optimum air-fuel ratios during all ranges of engine operation.

Fuel metering is accomplished through the use of 3 solenoids which add or reduce fuel to the engine. The solenoids operate at a fixed frequency generated by the Electronic Control Unit (ECU).

By varying the amount of time that a solenoid is energized during each duty cycle, the air-fuel mixture can be precisely controlled. The duty cycle applied to each solenoid is controlled by the ECU in response to signals received from various sensors.

There are 8 basic systems to the carburetor: fuel inlet, primary metering, secondary metering, accelerator pump, choke, jet mixture, enrichment and fuel cut-off.

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 1) Measure distance between bottom of float to surface of air horn. If distance is not 0.74"-0.82" (18.8-20.8 mm), adjust by adding or subtracting shim(s) under inlet needle seat.

Float Level Adjustment Make measurement without gasket. Scheme 1

Scheme 2

1. Remove water hose from choke assembly. Drill out staked portions of 3 choke cover screws. Using a small hammer and punch, remove remaining screw and choke cover.
2. Note relationship between painted punch mark and scribed lines on choke pinion plate, alignment of punch mark and line is essential during reassembly. (Scheme 2) (Scheme 2): Pinion Plate Alignment Align punch mark and line during reassembly.
3. Remove "E" clip from throttle opener link, then remove screws and throttle opener. Disconnect fuel cut-off solenoid ground wire and remove solenoid. Remove throttle return and damper springs. Remove "E" clips and choke unloader link.
4. Disconnect vacuum hose and vacuum chamber link. Remove screws and vacuum chamber. Remove throttle position sensor screws and sensor. Remove vacuum hoses from carburetor. Disconnect throttle rod link from throttle lever. Remove 6 air horn screws and remove air horn.
5. Slide float pivot pin out, remove float and inlet needle. Remove and discard gasket. Remove retainer, needle seat and screen assembly. DO NOT lose shim from under needle seat. Disconnect solenoid wiring and remove solenoids.
6. Remove venturi retainers, primary and secondary venturi, and "O" rings. Note jet numbers for proper installation, then remove primary and secondary main jets from pedestals. Remove pedestals and discard gaskets.
7. Remove bowl vent solenoid screws, solenoid, spring, "O" ring, and seal. Remove 3 enrichment valve screws, valve cover, spring, valve, gasket, and jet. Remove screw, lock plate, and primary jet. Repeat procedure for secondary jet.
8. Remove primary and secondary air bleed jets from top of air horn. Note size 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 (with check ball), and gasket.
9. Remove 3 jet air control valve screws, cover, spring, spring retainer, and diaphragm/seal from throttle body. Remove "E" clip from sub-EGR lever. Carefully slide pin from lever and sub-EGR valve, catch ball and spring which are retained inside valve by pin. DO NOT lose ball or spring. Remove valve and boot seal.

View of Chrysler Corp. (Mikuni) 2-Barrel Carburetor. Scheme 3

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. After cleaning parts in solvent, be sure to rinse well with hot water and blow dry with compressed air.

REASSEMBLY

1. Reverse disassembly procedure to reassemble. Primary and secondary main jet and air bleed jets can be identified by number stamped on them. Largest numbered jets should be installed on secondary side.
2. Align punch mark with scribed line of pinion plate. Align punch mark of cam lever with paint mark of pinion plate gear. (Scheme 2)and (Scheme 5). Install choke cover, tighten screws and peen over tamper-proof screws. Install remaining screw using a small hammer and punch. Install water hose.

Exploded View of Valve & Pump Assemblies for Chrysler Corp. (Mikuni) Carburetor. Scheme 4

Cam Lever Alignment. Scheme 5

SPECIFICATIONS

Note. Specifications not available. For reference view of components (Scheme 4)