If there are leaks in the intake manifold, the vacuum of the air entering the engine is reduced, which leads to a malfunction of one or more cylinders.
Removing
- Disconnect the wire from the negative battery terminal.
- Relieve the fuel pressure in the fuel system. See chapter «Reducing the pressure in the fuel system», given in section «Multipoint fuel injection system (MPI)».
- Drain the coolant from the engine cooling system.
- Remove the air filter.
- Remove the throttle body.
- Disconnect the PCV crankcase ventilation hose from the cylinder head cover fitting (pic. 3.55).
- Disconnect the vacuum hose.
- Loosen the clamp and disconnect the brake booster vacuum hose.
- Disconnect the connectors from the knock sensor, injectors, intake air temperature sensor, canister cleaning solenoid valve, and EGR solenoid valve.
- Remove the control wiring harness from the engine.
- Turn out a bolt and disconnect a wire of connection of a head of cylinders with «weight».
- Remove the bolts, disconnect the high pressure fuel hose and remove the O-ring (see fig. 3.36)
- Loosen the clamp and disconnect the fuel return hose.
- Turn out bolts and remove in gathering a fuel line, a pipe of return of fuel, atomizers and a regulator of pressure (pic. 3.56).
Pic. 3.55. 4G1-MPI engine intake manifold: 1 - PCV crankcase ventilation hose; 2 - vacuum hose; 3 - vacuum hose of the vacuum brake booster; 4 - knock sensor connector; 5 - injector connectors; 6 - connector for the temperature sensor of the air entering the engine; 7 - connector of the solenoid valve for cleaning the adsorber; 8 - EGR solenoid valve connector (EGR); 9 - control wiring harness; 10 - wire connecting the engine block with «weight»; 11 - high pressure fuel hose; 12 - fuel return hose
Pic. 3.56. 4G1-MP1 engine intake manifold:1 - fuel line, fuel return pipe, injectors and pressure regulator; 2 - spacer sleeve; 3 - vacuum hose; 4 - the upper bolt of the intake manifold support, 18 Nm; 5 - bracket; 6 - intake manifold; 7 - intake manifold gasket; 8 - intake manifold support; 9 - vacuum hose and vacuum tube; 10 - solenoid valve assembly; 11 - exhaust gas recirculation valve (EGR); 12 - gasket; 13 - filter, 13 Nm; 14 - temperature sensor of air entering the engine
Warning. When removing the fuel line, be careful not to drop the fuel injectors.
- Disconnect the vacuum hose from the EGR valve (EGR).
- Remove the upper intake manifold mounting bolt.
- Turn out bolts and remove an arm.
- Remove the bolts and nuts and remove the intake manifold and intake manifold gasket.
- Turn out bolts and remove a support of an inlet collector.
- Remove the vacuum hose and vacuum tube.
- Remove the bolts and remove the solenoid valve assembly.
- Turn out bolts and remove the valve of system recirculation of the fulfilled gases (EGR) and padding.
- Turn out the filter and the gauge of temperature of the air coming to the engine.
Examination
- Check intake manifold for cracks or other damage.
- Check graduation (vacuum) channel for blockage.
- Using a metal ruler and feeler gauges, measure the flatness of the mating surface of the intake manifold.
Deviation from the flatness of the mating surface of the intake manifold:
- nominal: no more than 0.15 mm
- maximum allowable: 0.20 mm
Installation
- Installation is carried out in the reverse order of removal, taking into account the following.
- When installing the fuel hose (high pressure, lubricate the O-ring with a small amount of clean engine oil (pic. 3.36).
Warning. Do not allow oil to enter the fuel line.
- Slightly turning the fuel hose flange to the right or left, carefully insert it into the fuel line so as not to damage the O-ring. After installation, check that the hose turns smoothly in the fuel line.
- If the hose flange sticks when turning, the cause may be a damaged O-ring. Detach the flange (complete with hose) from the fuel line and check the gasket for damage, then reinsert it and check for smooth turning.
- Screw in bolts of fastening of a fuel hose of a high pressure and tighten them the demanded moment.
- Install the throttle assembly.
- Install the air filter.
- Pour coolant into the engine cooling system.
- Connect the wire to the negative battery terminal.