Intake Manifold: Service and Repair

V6-229, 262 & ALL V8 ENGINES EXC. 1984-88 CORVETTE & 1985-88 V8-305 W/EFI

1. Disconnect battery ground cable, drain cooling system and remove air cleaner.
2. Disconnect accelerator, transmission and cruise control linkages, as equipped.
3. Disconnect fuel line from carburetor or TBI unit and remove fuel line clips as needed.
4. Disconnect necessary vacuum hoses and electrical connectors, noting position for installation.
5. Disconnect upper radiator and heater hoses from manifold.
6. Disconnect high tension leads from spark plugs in right side of engine and remove distributor cap, rotate crankshaft until No. 1 cylinder is at TDC on compression stroke, mark position of distributor rotor, then remove distributor.
7. Remove ignition coil, AIR pump, cruise control servo and brackets, as needed.
8. Remove generator upper mounting bracket and EGR solenoids.

Fig. 6 Intake manifold tightening sequence. 1982---84 V6-229 & 1982---88 V8 carbureted engines:

Fig. 7 Intake manifold installation.:

Fig. 8 Intake manifold tightening sequence. 1985---88 V6-262 engine:

9. Remove manifold retaining bolts and the manifold. It may be necessary to remove carburetor, EGR valve and/or idle control solenoid to provide clearance for manifold bolt removal.
10. Ensure surfaces are clean and dry, then apply 3/16 bead of RTV sealer on each block ridge and apply suitable sealer around water outlets, install gaskets and secure gasket position by extending bead of sealer approximately 1/2 inch onto gasket ends.
11. Install manifold and retaining bolts, ensuring areas between case ridges and manifold are completely sealed.
12. Torque manifold bolts to specifications in sequence shown in Figs. 6, 7 and 8, then reverse remaining procedure to complete installation.




1985-88 V8-305 W/EFI

1. Disconnect battery ground cable, drain cooling system and remove air intake duct.
2. Disconnect accelerator, cruise control and transmission cables, as equipped.
3. Disconnect coolant hoses, electrical connectors, and the vacuum and breather hoses from throttle body, noting position for installation.
4. Remove throttle body from plenum, then remove distributor shield.
5. Disconnect brake booster and vacuum hoses from plenum, noting position for installation.
6. Connect pressure gauge J-34370-1 or equivalent to pressure tap on fuel rail, position bleed hose in suitable container and slowly relieve fuel system pressure. Failure to relieve system pressure prior to disconnecting fuel system components may cause fire or personal injury.

Fig. 9 Plenum, runner & fuel line installation. 1985---88 Corvette, 1985---88 V8-305 W/EFI similar:

Fig. 10 Intake manifold installation. 1985---88 Corvette & V8-305 W/EFI:

7. Disconnect canister control valve pipe, remove right side runners and plenum bolt, then remove plenum,Fig. 9.
8. Disconnect fuel line to cold start valve and remove valve.
9. Disconnect fuel lines from fuel rail and electrical connectors from injectors.
10. Loosen fuel rail retaining bolts and raise rail assembly.
11. Remove remaining manifold runners and the fuel rail assembly.
12. Rotate crankshaft until No. 1 cylinder is at TDC on compression stroke, remove distributor cap and mark position of distributor rotor, then remove distributor.
13. Disconnect EGR solenoid and all necessary electrical connectors, then remove manifold retaining bolts and the manifold.
14. Ensure surfaces are clean and dry, then apply 3/16 bead of RTV sealer on each block ridge and apply suitable sealer around water outlets, install gaskets and secure gasket position by extending bead of sealer approximately 1/2 inch onto gasket ends.
15. Install manifold and retaining bolts, ensuring areas between case ridges and manifold are completely sealed.
16. Torque manifold bolts to specifications in sequence shown in Fig. 10, then reverse remaining procedure to complete installation.