Astro Van M V6-262 4.3L VIN B TBI (1991)
Fig. 7 Lower Intake Manifold Bolt Tightening Sequence. VIN W
Fig. 8 Upper Intake Manifold Bolt Tightening Sequence. VIN W
1.
Disconnect battery ground cable.
2.
Remove engine cover, air cleaner and intake duct, Fig. 6.
3.
Remove upper intake as follows:
a.
Disconnect electrical harness from throttle position sensor (TPS), idle air control motor (IAC) and manifold absolute pressure (MAP) sensor.
b.
Remove communicator valve.
c.
Disconnect throttle and TV linkage from upper intake manifold.
d.
Remove ignition coil, then disconnect PCV hose at upper intake manifold.
e.
Remove vacuum hoses at front and rear of upper intake manifold.
f.
Disconnect A/C line at compressor, if equipped.
g.
Remove upper intake manifold attaching bolts and studs. Mark location of all studs for proper installation.
h.
Remove upper intake manifold.
4.
Remove lower intake manifold as follows:
a.
Remove distributor assembly, then mark position of distributor housing and rotor for proper installation.
b.
Remove upper radiator hose at thermostat housing, then disconnect heater hose at lower intake manifold.
c.
Disconnect fuel supply and return lines at rear of lower intake manifold.
d.
Disconnect electrical harness from fuel injector, EGR valve and coolant temperature sensor.
e.
Remove intake manifold attaching bolts, then the intake manifold.
5.
Reverse procedure to install, noting the following:
a.
Torque lower intake manifold attaching bolt to 35 ft. lbs. in sequence shown, Fig. 7.
b.
Torque upper intake manifold attaching bolt to 124 inch lbs. in sequence shown, Fig. 8.
