Intake Manifold: Service and Repair

1. Disconnect battery ground cable.
2. Remove air inlet hoses from air cleaner and throttle body.
3. Disconnect throttle cable from linkage at throttle body.
4. Remove throttle cable bracket attaching bolts, then position cable and bracket aside.
5. Release fuel system pressure as follows:
a. Connect fuel pressure gauge (part No. T80L-9974-B) with extension hose (part No. D85L-9974-B) to Schrader valve on fuel supply manifold.
b. Position drain hose in a suitable container and depress drain valve.
6. Disconnect fuel lines from fuel supply manifold and pressure regulator.
7. Disconnect the following electrical connectors and position aside: air charge temperature sensor; idle speed control valve; throttle position sensor; engine coolant temperature sensor.
8. Label and disconnect vacuum hoses from intake manifold, manifold plenum and throttle body.
9. Drain cooling system, then remove hose from thermostat housing to radiator.
10. Unfasten and remove EGR tube from throttle body.
11. Remove throttle body/plenum assembly attaching bolts and the assembly from intake manifold.
12. Remove distributor cap and wires as an assembly, then disconnect distributor electrical connector.
13. Mark position of distributor rotor and housing for assembly reference, then remove hold-down screw and clamp and the distributor assembly.
14. Remove valve cover attaching bolts and the valve cover.
15. Remove intake manifold attaching bolts and the intake manifold. Note length of attaching bolts for assembly reference.

Fig. 2 Intake manifold bolt tightening sequence:

16. Reverse procedure to install, noting the following:
a. Apply suitable sealant to manifold prior to gasket installation.
b. Ensure tab on right hand cylinder head gasket fits in cutout on intake manifold.
c. Hand-tighten retaining nuts onto studs 3 and 4, then torque retaining nuts and bolts as shown in Fig. 2.
d. Torque valve cover attaching bolts to 4-5 ft. lbs. and EGR tube-to-throttle body attaching bolts to 6-9 ft. lbs.
e. Torque throttle body/plenum assembly attaching bolts first to 7 ft. lbs., then to 15-18 ft. lbs.