GM 10031385 Manifold Asm,Intake

If the engine has been removed from the car, disregard the following steps which do not apply. First, if the vehicle is equipped with air conditioning, carefully examine the routing of the A/C hoses and the mounting of the compressor, as it may be possible to remove the intake manifold without disconnecting the A/C system; if in doubt, consult a certified dealer or refrigeration specialist to have the system depressurized, and do not disconnect the A/C hoses while the system is under pressure. Next, disconnect the negative battery cable and drain the coolant from the radiator. Remove the air cleaner assembly, noting the position of all hoses and pipes, then disconnect the upper radiator hose and the heater hose from the intake manifold. Disconnect the accelerator linkage at the carburetor, ensuring any supporting bracket on the manifold is also removed. With a container handy to catch any spillage, disconnect the fuel inlet hose at the carburetor, plugging the end to prevent dirt from entering the system and excessive fuel seepage. Disconnect all other hoses connected to the carburetor, identifying each hose with strips of numbered tape to prevent confusion upon reassembly. Remove the distributor, ensuring the distributor cap with spark plug wires is taped or wired out of the way, and then remove both rocker arm covers. Disconnect the vacuum hose leading to the power brake booster if equipped, and remove any accessory brackets attached to the intake manifold. Remove the external EFE pipe from the rear of the manifold, followed by the intake manifold-to-cylinder head attaching bolts. Lift the manifold, complete with carburetor, free from the engine without prying on the mating surfaces to avoid damage. If replacing the intake manifold, transfer all components that have not yet been removed, including the carburetor and its attaching bolts or studs, temperature or oil pressure sending unit, heater hose and water pump hose adapter fittings, EGR valve with a new gasket, emission system TV switches, and carburetor choke assembly. Before installing the manifold, place clean lint-free rags in the engine cavity and thoroughly clean the engine block, cylinder heads, and manifold gasket surfaces, ensuring all extra gasket material and sealing compound are removed. Clean the sealing surfaces of the cylinder case's front and rear ridges with degreaser, then apply a 3/16 in (5 mm) diameter bead of RTV or equivalent sealant on each ridge. Install the new intake gaskets on the cylinder heads, ensuring the correct gasket is used for each head, and hold the gaskets in place by extending the bead of RTV onto the gasket ends. Carefully lower the intake manifold into position, ensuring the gaskets are not disturbed, then install the intake manifold mounting bolts and tighten them in sequence, gradually torquing them to specifications. Finally, install the remaining components in the reverse order of removal, fill the radiator with coolant, start the engine, check for leaks, and adjust the ignition timing and carburetor idle speeds as necessary.

Loose the cable from the negative battery terminal, while doing so unscrew all the hoses from the air cleaner assembly, mark them by number and label them in an organized manner so as to know where to reconnect each one of them. Refer to the existing wear elements for their description, location and function that is as follows: Label, and then removed the fuel line and vacuum line connected to the throttle body, plus the electrical connector; do have a container ready for fuel which will come dripping once you unhook the fuel line and cap it. Remove the throttle linkage and make sure you take note where it was, and remove the cruise control linkage if installed. Pull the coil wire out, then unscrew the two brass retaining screws and one steel bolt and then extracted the coil. Disconnected the coolant hoses from the manifold, then use the manifold retaining bolts to loose the manifold from the cylinder head without levering or tapping between them in order not to damage the gasket sealing surfaces. Take off the manifold gasket, and if necessary, reinstall all components which are already connected to the old manifold to the new one. Before installing the cylinder head or manifold gasket, it is recommended that the sealing surfaces of both the cylinder head and manifold gasket be cleaned completely of all gasket material and sealing compound. Run an RTV-type silicone sealant around the intake manifold and the cylinder head flanges so that it will not ooze into air or water passages when tightening the bolts. Put a fresh intake manifold gasket on the manifold, align the manifold to the cylinder head, and put the mounting bolts just enough to been turned by hand. It is recommended that the mounting bolts should be tightened gradually in this sequence to the specified torque range. Reinstall the remaining components in the reverse order of removal, pour more coolant in the radiator, switch on the engine and look for evidence of the leak, rectify the ignition timing and the idle speed as required.

To remove the components, first disconnect the cable from the negative battery terminal and remove the air cleaner assembly, tagging each hose with numbered or colored tape for easier installation. Relieve the fuel pressure and drain the cooling system. Remove the PCV valve and hose at the throttle body housing, then label and disconnect the fuel line fittings at the throttle body, removing the fuel filter bracket bolt underneath. Label and disconnect the vacuum lines and electrical leads from the fuel injection assembly. Disconnect the throttle cable from the throttle linkage by prying off the C-clip and popping off the linkage rod, noting its installation. If equipped with an automatic transmission, disconnect and remove the transaxle downshift linkage, and if cruise control is present, disconnect the linkage. Disconnect the heater hose fitting located on the underside of the intake manifold. Remove the forward strut rod through-bolt adjacent to the cylinder head, then remove the access plate in the top of the right fender well to access and remove the rear through-bolt, followed by the strut rod. Disconnect the alternator by removing the belt tensioning nut and bolt, then remove the alternator bracket. Disconnect the coil mounting nuts, coil lead, and coil wire, then remove the coil. Remove the intake manifold mounting bolts and separate the manifold from the cylinder head without prying to avoid damaging the gasket sealing surfaces. Remove the intake manifold gasket with a gasket scraper, ensuring no material remains on the mating surface. For installation, if replacing the intake manifold, transfer all components from the old manifold to the new one. Clean the cylinder head and manifold gasket surfaces, ensuring all gasket material and sealing compound are removed. Place a new intake manifold gasket on the manifold, hold it against the cylinder head, and install the mounting bolts finger tight. Tighten the mounting bolts gradually in the proper sequence to the specified torque, then push the electrical connectors back through the intake manifold. Install the alternator bracket, adjust the alternator belt tension, and install the strut rod with both through-bolts, tightening them to the specified torque before replacing the fender well through-bolt access plate. Place the TBI linkage rod into position and reattach the throttle cable, then reattach the heater hose fitting to the underside of the intake manifold. Reconnect the fuel feed and return lines, installing the fuel filter bracket mounting bolt, and reattach the PCV valve, elbow, and hose between the rocker arm cover and the TBI housing. Reattach the remaining vacuum lines and electrical connectors, install the coil assembly, and reconnect the coil lead and coil wire. Finally, install the air cleaner, fill the radiator with coolant, start the engine, and check for leaks.

Pull out the air cleaner and make notations on the lines and hoses as to their location; next, pull out the PCV hose and lastly, remove the negative battery terminal. Siphon the cooling system and dismount the carbureter or throttle body body put together with its base gasket. Remove the vacuum lines from the carburetor spacer and then unscrew the EGA valve, and then the carburetor spacer along with its gasket. There will also be removal of the bell crank and throttle linkage brackets to avail room, and modification of the heater hose from the intake manifold as well as the upper generator bracket. If fitted, remove the PULSAIR air valve bracket, then the intake manifold to cylinder head bolts and the manifold along with the gasket. Incase you are integrating the project of replacing the intake manifold, then ensure you transfer over all the remaining parts from the old one to the new one. Put unbleached cotton waste pads over the engine and if possible, clean all the sealing surfaces of the engine block with a lint free rag, the cylinder head and the manifold gasket surfaces properly removing all the gasket material and the sealing compound. Squash a thin line of RTV or equivalent sealer to the meeting surfaces, but do not intrude into the air or water channels. Place a new intake manifold gasket on the manifold, put the manifold on the cylinder head and tighten the mounting bolts only hand-tight. Loosening the bolts in a sequence until they reach the torque of the system recommended torque gradually. The last packages should be reinstalled, refilling of the radiator with coolant followed by running of the engine and realized that there is no leakage before adjustment of the carburetor for the idle speeds.

Pull out the air cleaner and make notations on the lines and hoses as to their location; next, pull out the PCV hose and lastly, remove the negative battery terminal. Siphon the cooling system and dismount the carbureter or throttle body body put together with its base gasket. Remove the vacuum lines from the carburetor spacer and then unscrew the EGA valve, and then the carburetor spacer along with its gasket. There will also be removal of the bell crank and throttle linkage brackets to avail room, and modification of the heater hose from the intake manifold as well as the upper generator bracket. If fitted, remove the PULSAIR air valve bracket, then the intake manifold to cylinder head bolts and the manifold along with the gasket. Incase you are integrating the project of replacing the intake manifold, then ensure you transfer over all the remaining parts from the old one to the new one. Put unbleached cotton waste pads over the engine and if possible, clean all the sealing surfaces of the engine block with a lint free rag, the cylinder head and the manifold gasket surfaces properly removing all the gasket material and the sealing compound. Squash a thin line of RTV or equivalent sealer to the meeting surfaces, but do not intrude into the air or water channels. Place a new intake manifold gasket on the manifold, put the manifold on the cylinder head and tighten the mounting bolts only hand-tight. Loosening the bolts in a sequence until they reach the torque of the system recommended torque gradually. The last packages should be reinstalled, refilling of the radiator with coolant followed by running of the engine and realized that there is no leakage before adjustment of the carburetor for the idle speeds.

Installation involves cleaning gasket surfaces, applying sealer, placing gaskets, and securing the manifold bolts.

Apply a 3/16-inch wide bead of RTV sealant to the front and rear manifold mating surfaces of the block, and a thin coat of RTV sealant around the coolant passage holes on the cylinder head side of the new intake manifold gaskets.

Carefully lower the intake manifold into position, ensuring the gaskets remain undisturbed, then install and tighten the mounting bolts according to the recommended sequence.

Disconnect the fuel line inlet and return fittings at the fuel block, then disconnect the wires from the fuel injectors.

Disconnect all other hoses connected to the carburetor, identifying each with numbered tape to avoid confusion during reassembly.

Connect or re-install the components in the reverse order of removal, reconnect the battery cable, close the drain plug, and refill the cooling system.