Intake Manifold: Service and Repair

1. Disconnect battery ground cable, then drain coolant to appropriate level.
2. Disconnect vacuum hose and electrical connector from MAP sensor.
3. Disconnect air cleaner to throttle body duct.
4. Disconnect vent tube to air cleaner duct.
5. Remove throttle cable bracket, then disconnect power brake unit vacuum hose with retaining bracket to power steering bracket and position aside.
6. Remove throttle body from intake manifold and position aside with electrical connector, coolant hoses, vacuum hoses and throttle cable attached.
7. Remove oil/air separator, leaving hoses attached to the separator. Disconnect hoses from the oil fill, chain housing, chain cover, intake duct and intake manifold and remove as an assembly.
8. Remove oil fill cap and dipstick assembly, then pull oil fill tube upward to unseat from engine block.
9. Disconnect injector wiring harness connector.
10. Remove oil fill tube out top, rotating as necessary to gain clearance for oil/air separator nipple between intake tubes and fuel rail electrical harness.

Fig. 8 Intake Manifold Brace Removal. 1989-91:

Fig. 9 Intake Manifold Brace Removal. 1992:

Fig. 10 Intake Manifold Installation & Bolt Tightening Sequence. 1989-91:

Fig. 11 Intake Manifold Installation & Bolt Tightening Sequence. 1992:

11. Remove intake manifold support bracket, Figs. 8 and 9.
12. Remove remaining intake manifold attaching bolts and nuts, then remove intake manifold and gasket.
13. Reverse procedure to install. Tighten intake manifold bolts in sequence shown in Figs. 10 and 11.