Crankcase ventilation system
Note. Crankcase ventilation box. located on the cylinder head cover.
Crankcase ventilation outlet (engines F4P - K4M) |
Crankcase ventilation inlet (F4P - K4M engines)
Branch in front of the throttle body
This branch is used for medium and high engine loads. Vapors are absorbed due to the rarefaction created by 8 air duct 7.
Branch after throttle body
This branch is used for low engine loads. Vapors are absorbed by the vacuum created between the throttle valve and the engine.
Attention! During normal operation, the vent to atmosphere must not be blocked.
Principle of operation
Communication with the atmosphere of the fuel tank is carried out through the fuel vapor absorber.
Gasoline vapors are retained by activated carbon contained in the absorber.
Gasoline vapors contained in the absorber are eliminated by burning them in the engine.
To do this, the absorber is connected to the intake manifold by means of a pipeline and a solenoid valve. The solenoid valve is located on the cup of the right front mudguard on the F4P, K4M engines. F5R and next to the power steering reservoir on the L7X engine.
The principle of operation of the solenoid valve is based on changing the flow area (according to the signal of the degree of cyclic opening, generated by the injection computer).
The change in the flow area of the channel for the passage of fuel vapor in the solenoid valve occurs due to the balance between the magnetic field created by the passage of the supply current through the winding and the force of the return spring, which ensures the closure of the solenoid valve.
Checking the absorber purge
A malfunction of the system may result in erratic idling or engine shutdown.
Make sure the system piping is properly connected (see function diagrams).
Check up a condition of pipelines to a fuel tank.
Absorber Purge Conditions
The absorber purge solenoid valve is controlled from terminal C-E1 on the K4M and F4P engines and from terminal C-F4 on the L7X engine) ECU under the conditions listed below.
F4P and K4M engines:
- coolant temperature above 55°C;
- air temperature above 10°С;
- the engine is not in idle mode;
- the specified load threshold has been reached;
- throttle position sensor out of position «idling».
L7X engine:
- coolant temperature above 35°C;
- the time delay after start is 20 s.
When performing diagnostics using the on-board diagnostic system, the absorber purge is not allowed.
It is possible to visually display the degree of cyclic opening of the absorber purge solenoid valve using diagnostic tools, see parameter «Degree of cyclic opening of the absorber purge solenoid valve».
The solenoid valve is closed if the value is below 1.5%.
Removing the absorber
Absorber 1 is located above the left side of the fuel tank.
Disconnect:
- pipeline 2 for supplying vapors from the fuel tank;
- pipeline 3 for removing vapors to the solenoid valve;
- tube 4 messages with the atmosphere.
Remove bolt 5 fastening and absorber.
Installation
Installation is made in an order, the return to removal.