Disassemble
Fig. 3a Typical exploded view of Rochester E4M series carburetor (Part 1 of 2):
E4M EXPLODED VIEW PART 1 OF 2
Fig. 3b Typical exploded view of Rochester E4M series carburetor (Part 2 of 2):
E4M EXPLODED VIEW PART 2 OF 2
Fig. 4 Removing pump lever roll pin:
1. Remove screws and then idle speed control, idle load compressor, or idle speed solenoid from float bowl to prevent damage from carburetor cleaner.
2. Remove retaining screw, then upper choke lever from end of choke shaft. Rotate lever to remove from choke rod.
3. Hold lower choke lever outward with small screwdriver and twist choke rod counterclockwise to remove from lever.
4. Remove small screw in top of metering rod hanger. Lift up on metering rod hanger until secondary metering rods are completely out of air horn. Remove metering rods from hanger by rotating ends out of holes in hanger.
5. Using drift punch, drive roll pin in until pump lever can be removed from air horn, Fig. 4. Then, remove pump lever from link.
6. Remove front vacuum break hose noting tube locations for reassembly.
Fig. 5 Air horn screw location & tightening sequence:
7. Remove 11 air horn to bowl screws and lockwashers, then remove 2 countersunk screws next to venturi, Fig. 5. Remove secondary air baffle deflector (if equipped) from beneath 2 center air horn screws.
8. Remove air horn from float bowl by lifting straight up. Leave air horn gasket on float bowl for later removal. While removing air horn, take care not to damage solenoid connector, throttle position sensor (TPS) adjustment lever, or pull over enrichment tubes (if used).
9. Remove front vacuum break screws, then vacuum break assembly from air valve rod. Remove air valve rod from air valve lever.
10. Remove throttle position sensor plunger by pushing up through seal in air horn.
11. With air horn inverted, drive lean mixture screw plug out of air horn from bottom side using suitable punch. Discard plug.
12. If necessary to replace rich mixture screw, or to readjust mixture control solenoid travel, remove rich mixture screw using tool BT-7967A or equivalent. With stop screw removed, drive plug out of air horn to gain access to stop screw (when installed). Discard plug.
13. Using small screwdriver, remove staking holding throttle position sensor seal retainer in place. Remove and discard retainer and seal. Further disassembly of air horn is not required for cleaning purposes. Air horn assembly with idle air bleed valve in place should be cleaned only using a low volatile cleaning solvent to avoid damaging O-rings sealing bleed valve.
14. If Computer Command Control system diagnosis indicates carburetor is causing problems with engine performance, fuel economy, or exhaust emissions, tamper resistant cover shielding idle air bleed valve can be removed as follows:
a. Support air horn and align #35 drill bit (.110 inch) on steel rivet head holding idle bleed valve cover in place. Drill only enough to remove rivet head, then drill remaining rivet head. Using drift and small hammer, drive remainder of rivets out of idle air bleed valve tower in air horn casting.
b. Lift out cover and remove remainder of rivets from inside tower. Discard cover.
c. Using screwdriver, turn bleed valve counterclockwise to remove. Remove and discard O-rings from valve. Do not place air horn assembly in carburetor cleaner with idle air bleed installed.
15. While holding down on pump plunger stem, lift corner of air horn gasket and remove pump plunger from pump well.
16. Remove solenoid metering rod plunger.
17. Remove rubber seal from around mixture control solenoid connector.
18. Lift air horn gasket off of dowel pins on float bowl. Discard gasket.
19. Remove pump return spring from well.
20. Remove staking holding throttle position sensor (TPS) in place as follows:
a. Place suitable metal piece across bowl casting to protect gasket surface from prying forces.
b. Using small screwdriver, lightly depress and hold TPS down against spring tension.
c. Carefully pry upward with suitable chisel to remove bowl staking, taking care that prying force is exerted against metal piece.
d. Push up on electrical connector to remove TPS from bowl taking care not to damage part.
e. Remove spring from bottom of well.
21. Remove plastic filler block over float chamber.
22. Carefully lift each primary metering rod out of jet, making sure that return spring is removed with each metering rod. Then, remove return spring by sliding off end of rod.
23. Remove mixture control solenoid from float bowl as follows:
a. Remove solenoid connector screw. Do not remove connector at this point.
b. Using tool BT-7928 or equivalent, on upper end of lean mixture adjustment screw, note number of turns required (clockwise) to bottom screw lightly. Record number of turns for later use. Then, turn screw counterclockwise and remove.
c. Carefully lift mixture control solenoid and connector assembly from float bowl.
d. Do not remove plunger return spring or connector from float bowl. Do not remove plunger return spring or connector and wires from solenoid body.
e. Remove plastic insert (if used) from cavity in float bowl beneath solenoid connector.
f. Remove lean mixture screw tension spring.
24. Remove float assembly and float needle by pulling up on retaining pin. Using tool BT-3006M or equivalent, remove needle and seat gasket.
25. Remove large mixture control solenoid spring from boss on bottom of float bowl located between metering jets.
26. If necessary, remove primary metering jets using tool BT-7928 or equivalent. Do not attempt to remove secondary metering jets (orifice plates) since they are fixed and, if damaged, fuel bowl replacement will be necessary.
27. Remove pump discharge check ball retainer. Turn fuel bowl upside down to remove check ball.
28. Remove secondary air baffle, if necessary.
29. If necessary, remove pump well fill slot baffle.
30. Remove hose from rear vacuum break, if used. Then remove 2 screws from bracket and rotate assembly to remove vacuum break rod or link from slot in plunger head.
31. Support float bowl and throttle body assembly on suitable fixture.
32. Using #21 drill bit (.159 inch), carefully drill off choke cover rivet head. Using drift and hammer, drive remainder of rivets out of choke housing.
33. Remove 3 retainers, choke cover gasket (if used), and choke cover assembly from choke housing. On models with hot air choke, do not remove baffle plate from beneath thermostatic coil on choke cover.
34. On all models, remove retaining screw and washer inside choke housing, then choke housing by sliding outward.
35. On models with hot air choke, remove plastic tube seal from vacuum inlet boss on choke housing.
36. On all models, remove rear vacuum break rod or link (if used) from intermediate choke lever.
37. Remove secondary throttle valve lockout lever from float bowl.
38. Remove choke coil lever retaining screw at end of intermediate choke shaft and remove lever. On models with hot air choke, remove cup seal inside choke housing shaft hole if housing will be immersed in carburetor cleaner.
39. Slide intermediate choke shaft from choke housing. Then, remove fast idle cam from intermediate shaft.
40. Remove cup seal from float bowl insert for cleaning. Do not attempt to remove insert.
41. Remove lower choke rod lever from inside float bowl housing.
42. Remove fuel inlet nut, gasket, check valve filter assembly, and spring.
43. Remove 3 throttle body to fuel bowl screws and lock washers, then throttle body assembly.
44. Remove insulator gasket.
45. Place throttle body assembly on carburetor holding fixture.
46. Rotate pump link until tang aligns with slot in lever, then remove link.
47. Do not remove concealment plugs on mixture needles for cleaning.