Jeep Grand Cherokee

1993-1999 of release

Repair and car operation

Jeep Grand Cherokee
+ Cars of mark Jeep Grand Cherokee
+ Options and routine maintenance
+ Рядный the six-cylinder engine
+ Engine V8
+ Procedure of the general and engine major repairs
+ Systems of cooling, heating and air conditioning
+ The power supply system and release of the fulfilled gases
+ System of an electric equipment of the engine
- Systems of decrease in toxicity of the fulfilled gases and engine management
   The general information
   System of multiitem injection of fuel (MPFI) and information gauges - the description
   Removal and installation of the electronic module of management (РСМ)
   The description of a principle of action of system of self-diagnostics and procedure of reading of codes of malfunctions
   Information gauges
   System of operated ventilation картера (PCV)
   System recycling the fulfilled gases (EGR)
   System of catching of steams of fuel (EVAP)
   The Katalitichesky converter
+ Manual box of a gear change
+ Automatic transmission
+ Distributing box
+ Coupling and трансмиссионная a line
+ Brake system
+ Suspension bracket and steering
+ Body
+ System of an onboard electric equipment
+ Controls and operation receptions


System of catching of steams of fuel (EVAP)

The general description

System EVAP carries out adsorption of steams of fuel and their burning as a part of a gas mixture during normal functioning of the engine.

The structure of any system of catching of steams of fuel necessarily includes the adsorber filled with activated coal in which gathering of steams of gasoline is carried out. Difference of one system from another can consist in realisation management of a conclusion of evaporations. The description of the system typical for models of mark described in a given Management of cars which should supply the owner with the information, sufficient for understanding of a principle of a conclusion of steams of fuel on its car is more low resulted.

The description resulted more low does not apply for unequivocal conformity to the description of the system used on the concrete car, however provides guidance on to the typical scheme accepted for a conclusion of steams of fuel on models, equipped with system of injection of fuel. Despite that presence of all listed below components is obligatory in any system EVAP, on the concrete car the additional devices which are the unique can be quite included. Be verified with given label VECI and the scheme of a lining of the vacuum hoses located under a cowl of the car.

The cover of a mouth of a gulf of fuel is equipped by a double-thread safety valve. The valve serves for a conclusion in atmosphere of the evaporations which have accumulated in a fuel tank in default systems EVAP.

Other cutting (unloading) valve is established on a fuel tank and serves for adjustment of a conclusion of steams of fuel from a tank in a coal adsorber depending on presence at a tank of superfluous or negative pressure (depending on an ambient temperature).

After passage of the double-thread valve fuel evaporations on ventilating hoses arrive in the coal adsorber located in an impellent compartment where they are adsorbed by the activated coal and are stored to a conclusion in chambers of combustion of the engine.

Site of a coal adsorber of system EVAP.

When the engine is started and warmed up to in advance established temperature the cutting electromagnetic valve of a purge near to an adsorber closed, providing opening by depression of the inlet pipeline диафрагменного the valve of management with an adsorber purge. Thus fuel steams are deduced from an adsorber also under the influence of depression of the inlet pipeline.

The electromagnet of management is located by an adsorber purge on an engine left-hand side, in the neighbourhood with TPS.


Full check of system EVAP lies out of limits of qualification of the average mechanic-fan. Fortunately the system of catching of steams, as well as any other subsystem of system of decrease in toxicity of the fulfilled gases gets under manufacturer guarantee certificates (5 years, or 80 000 km (50 000 miles) run at the moment of drawing up of the given Management). Probably, the system will not fail never during all service life of the car, however, in any case it is necessary to check from time to time a condition of its hoses and a coal adsorber.

Always first of all check a condition of hoses, the detachment or which damage appears system EVAP cause of a failure more often. For check of correctness of connection of hoses be verified with the scheme of a lining of vacuum hoses put on шильду, fixed on a radiator support under a car cowl. In case of need make repair or replacement of the damaged hoses.


    Disconnect a vacuum hose from диафрагменного the valve of a purge of an adsorber (it is located on the inlet pipeline) and connect to a hose the vacuum gauge. Start the engine and leave its working on single turns. Depression in a hose should not be!

The engine temperature at this check should reach 75,5 With.

    At the heated-up engine depression should be absent (alarm depression from the electromagnetic valve of management of an adsorber purge).
    If depression is absent, pass to performance of procedures of item 8. If depression takes place, disunite an electric socket of an electromagnet of management of a purge and check up it on presence of a food from the battery.
    Check up presence of pressure of the battery on an electromagnet of management of an adsorber purge.
    If pressure takes place, replace cutting electromagnetic valve. If pressure is not present, check up a condition of a plait of wires РСМ, in case of need make repair. Warm up the engine to normal working temperature. If originally depression on диафрагменном the valve of management of a purge was absent, check up a depression source. If depression takes place, pass to item 11. If depression is not present, check up the vacuum line going to the inlet pipeline on presence of damages or infringement of passableness of unions. If the vacuum in an initial condition depression takes place, check up functioning перекидного the valve of a fuel tank in a workshop of dealer branch.

The unloading valve of a fuel tank


    Remove a fuel tank (the Head of the Power supply system and release of the fulfilled gases). The valve is planted in the rubber plug through passage. Take it, having hooked on the one hand and having turned out the plug from a tank together the valve.

The unloading valve of a fuel tank is located in a fuel tank.

    Installation make upside-down.