WORKSHOP MANUAL - lombardini service

Disassembly / Reassembly
4
Intake manifold – Remote air filter
2 2
1
- Unscrew the the fastening screws 1 that fix the intake duct to the
intake manifold unit.
- Unscrew the two fastening screws 2 of the intake manifold from
the engine crankcase.
- Disassemble the inlet manifold by disengaging the hook of the
min/max cylinder from the manifold.
1
2
2
1
4
E.G.R. CIRCUIT
6
Components:
5
13
7
2
12
10
8
1
11
1. Exhaust manifold
2. E.G.R. Pipe
3. E.G.R. Valve
4. Vacuum pump
5. Three way union
6. Vacuum pump pipe
7. Thermovalve – vacuum pump
connection pipe
8. Vacuum valve – thermovalve
connection pipe
9. Vacuum valve - E.G.R. connection
pipe
10. Thermovalve
11. Vacuum valve
12. ON-OFF sensor control cam
13. Intake duct
2
3 9
10 8
Operation
The main function of the E.G.R. (Exhaust Gas Recirculation) system is the reduction in emission of NOx (nitrogen oxides),
gases harmful to people and the environment, via lowering the combustion temperature.
The system takes a certain quantity of exhaust gas from the exhaust manifold 1 (fig. 2) via the E.G.R. pipe 2 to the E.G.R.
valve 3.
This valve is opened by the vacuum (created in pipes 6, 7, 8 and 9 by vacuum pump 4; fig. 2) only when:
a) thermovalve 10 placed in contact with the engine refrigerant fluid reaches a temperature of 40 °C;
b) the on-off sensor control cam 12 opens the vacuum valve 11 at a determined accelerator position.
Once the E.G.R. valve is opened, the exhaust gas enters the intake manifold 13 via the intake flange.
The same logic controls the closure of the E.G.R. valve.
FOCS Workshop Manual_cod. 1.5302.858_1° ed_ rev. 00
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