Nissan Patrol, Ford Maverick

1988-1997 of release

Repair and car operation


Nissan Patrol and Ford Maverik
+ Cars of the Nissan Patrol and Ford Maverick series
+ Diagnostics of malfunctions
+ Settings and routine maintenance
+ Engine
+ Systems of cooling, heating and air conditioning
+ the Power supply system and production of the fulfilled gases
- Systems of decrease in toxicity of the fulfilled gases
   System of ventilation of a case
   System of a retsirkulyatsiya of the fulfilled gases (EGR) - models of 3.0 l
   Control system of quality of a mix during a deseleratsiya
   Control system in temperature of soaked-up air
   System of catching of fuel evaporations (ECS)
+ Systems of electric equipment of the engine
+ Transmission
+ Coupling
+ Brake system
+ Forward and back bridges, running gear and steering
+ Body
+ Onboard electric equipment





System of a retsirkulyatsiya of the fulfilled gases (EGR) - models of 3.0 l

For performance of procedures of service of components of system the manual vacuum pump with the vacuum gage is required.

Action principle

Principle of functioning of EGR system
1 — the union of operating depression
2 — the atmosphere
3 — модулирующиу the valve
4 — the valve of management of EGR
5 — to the distributor
6 — TVV
7 — the inlet pipeline
8 — cooling liquid
9 — the fulfilled gases

In the purpose of decrease in level of the content of oxides of nitrogen in release system the part of the fulfilled gases goes back to the engine. The main components of system of a retsirkulyatsiya are the EGR valve modulating the valve and the thermovacuum valve (TVV) (the arrangement of the first of two on the engine is shown on an accompanying illustration).

The modulating valve operates depth of the depression submitted on the EGR valve for the purpose of maintenance of constant level of a retsirkulyatsiya of fulfilled gases.

At low temperature of cooling TVV liquid it is closed and blocks access of depression to the EGR valve, supports the last also in the closed condition.

When the temperature of cooling liquid reaches normal working value, TVV opens, providing access of depression to the modulating valve.

The diaphragm of the modulating valve is drawn in by the fulfilled gases from system of release and provides or blocks supply of air in a vacuum tube of the EGR valve, operating that opening/closing of the last.

At low loadings or small turns of the engine when pressure of the fulfilled gases is not enough, the spring of a diaphragm overcomes this pressure, opening supply of air. Respectively, the EGR valve remains closed.
At high loadings/turns of the engine pressure of the fulfilled gases also rises, overcoming resistance of a spring of a diaphragm and blocking supply of air. Thus the EGR valve is influenced by full depth of depression that lifts level of a retsirkulyatsiya of the fulfilled gases.

Check of functioning of system

 PERFORMANCE ORDER

    Check a condition of all vacuum hoses. Replace the defective. Start the engine and warm up it to normal working temperature. At the working engine open-close a butterfly valve, watching behavior of a diaphragm of EGR. The EGR valve should open and be closed at the same time with a zaslonka. If conditions of check are not carried out, check system components separately.
    EGR valve check Muffle the engine and disconnect a tube of giving of depression from the EGR valve. Connect the manual vacuum pump with the vacuum gage to the EGR valve and create depression by depth of 120 mm of mercury. The valve should open and remain smoothly open yet will depression is dumped, otherwise it is necessary to replace it.

Check of the modulating valve

 PERFORMANCE ORDER

    Enter a piece of a wire of suitable length the bottom union of the modulating valve. Slightly wring out a diaphragm and by means of the manual vacuum pump create depression on the top union of the valve. If the valve does not hold depression, it is possible to consider it faulty. Check of the thermovacuum valve Start the engine from a cold condition. Disconnect a vacuum hose from the top union of the modulating valve. Put a finger by the open end of a hose and increase engine turns. Depression it should not be felt. Warm up the engine to normal working temperature. Again put a finger by the end of a hose and lift turns. Now depression should be felt. In case of need replace TVV (TVV arrangement on the engine is shown on an accompanying illustration).

Check of the thermovacuum valve

 PERFORMANCE ORDER

    Start the engine from a cold condition. Disconnect a vacuum hose from the top union of the modulating valve. Put a finger by the open end of a hose and increase engine turns. Depression it should not be felt. Warm up the engine to normal working temperature. Again put a finger by the end of a hose and lift turns. Now depression should be felt.
    In case of need replace TVV (TVV arrangement on the engine is shown on an accompanying illustration).