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
   The general information
   Procedure of dump of pressure of fuel
   Check of pressure of fuel and functioning of the fuel pump
   Removal and installation of a fuel tank
   Cleaning and repair of a fuel tank - the general information
   Repair and replacement of fuel lines
   Removal and installation of the fuel pump
   Check of serviceability and replacement of the block of the gauge of level of fuel
   Removal and installation of assemblage of an air cleaner
   Replacement of a cable of gas
   System of injection of fuel - the general information
   Check of serviceability of system of injection of fuel
   Serviceability check, removal and installation of the case of a throttle
   Check of serviceability and replacement of a regulator of pressure of fuel
   Serviceability check, removal and installation of injectors of fuel
   Check of functioning and replacement of components of system of stabilisation of turns of idling (IAC)
   Service of system of release of the fulfilled gases - the general information
+ System of an electric equipment of the engine
+ Systems of decrease in toxicity of the fulfilled gases and engine management
+ 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

e65f60b7

Check of pressure of fuel and functioning of the fuel pump

The prevention in the beginning see Procedure of dump of pressure of fuel (the description of procedure of dump of pressure of fuel see in the same place) Has undressed.


Models 1995 вып. Are not equipped usual vacuum type by a regulator of pressure of fuel. Here the regulator is built in in the fuel pump. In case of occurrence of the problems connected with pressure of fuel replace entirely assemblage of the fuel pump/block of the gauge.

Primary check

If there are suspicions on deterioration of giving of fuel, first of all check up fuel lines on presence of signs of leaks.

Check of functioning of the fuel pump

On all models the fuel pump is located in a fuel tank (see Has undressed Removal and installation of the fuel pump).


 PERFORMANCE ORDER

    Cock a lay brake and ask the assistant to turn the ignition key in position ON. At this time listen to published by the pump in a fuel tank to sounds. It should be the hum lasting about 2 seconds. Start the engine. Now hum should become continuous (though he and will be more difficult for catching because of the working engine). If no sounds are present, is faulty either the pump, or its relay, or the relay of a contour of automatic switching-off of giving of fuel (ASD) (pass to item 1).

Pressure check

 PERFORMANCE ORDER

    Dump pressure of fuel (Section Procedure of dump of pressure of fuel). Uncover the union of check of pressure of the fuel located on a fuel highway and connect to the union a manometre.
    Connect a manometre to a fuel highway and consider its indications at the engine working on single turns (the model with the engine in volume 5.2 is shown).
Carrying out of check of pressure of fuel on the models equipped with the engine in volume of 4.0 l.
    Start the engine and consider manometre indications, having compared them to the data of Specifications. Now disconnect a vacuum hose from a regulator of pressure of fuel. Again at the engine working on single turns take readings of the device - it again should meet corresponding requirements. Connect a hose into place.

Models 1995 вып. Are equipped built in in the block of the fuel pump/gauge of level by a regulator of pressure of fuel, here there is a possibility of check of only adjusted pressure of fuel.


Models 1995 вып. Are equipped by the regulator of pressure of fuel built in in the fuel pump.

    If results of measurement of pressure of fuel do not meet requirements of Specifications, operate as follows:
      If the result of measurements meets the requirements of Specifications at connected to a pressure regulator a vacuum hose, however leaves for admissible limits at the disconnected hose, check up depression presence in a hose. If depression is present, replace a regulator (Section Check of serviceability and replacement of a regulator of pressure of fuel). If depression is not fixed, check up a hose on presence of breakages and corkings. If pressure exceeds admissible value check up passableness of a hose (or tubes of return of fuel). If passableness is not broken, replace a pressure regulator (Section Check of serviceability and replacement of a regulator of pressure of fuel). If the measured pressure below an admissible limit, do the following: Make sure that the fuel filter is not hammered. Whether check up it is overwound and whether the fuel hose between a petrol tank and a fuel highway is blocked. Check up serviceability of functioning of a regulator of pressure of fuel. Check up fuel lines on presence of signs of leaks.
    If any of refusals listed above components are not found out, check up serviceability of a condition of the fuel pump.

Components of a regulator of pressure of fuel

 PERFORMANCE ORDER

    Connect the vacuum pump to a regulator of pressure of fuel. Consider indications of a manometre without creating depression on a regulator and at depression. About increase in depth of depression pressure of fuel should fall. Compare results of measurements to the data of Specifications.

Models 1995 вып. Are equipped built in in the block of the fuel pump/gauge of level by a regulator of pressure of fuel (see an illustration). Thus, here there is a possibility of check of only adjusted pressure.


    Connect the vacuum pump to a regulator of pressure of fuel and measure pressure of fuel at first without creating depression.

... And then having created it is in the presence of depression pressure should fall.

    Connect a vacuum hose to a regulator and check up pressure of fuel at the engine working on idling, compare results of measurements to requirements of Specifications. Disconnect a hose and repeat check - pressure should jump up to the maximum admissible value right after hose detachments. If pressure upon single turns too highly (at the disconnected hose), connect to a hose the vacuum gauge and measure depth of depression in it. If pressure of fuel is too low, press a line of return of fuel and track change of indications of a manometre. If pressure has not increased, or the fuel pump is faulty, or passableness of a line of giving of fuel is broken. If pressure has jumped up, replace a regulator of pressure of fuel (Section Check of serviceability and replacement of a regulator of pressure of fuel).

It is required to make special rubber inserts between a fuel highway and a returnable line as steel metal lines cannot be pressed for the purpose of performance of the given check.

    If the manometre indication too highly, disconnect a line of return of fuel and try to blow it for passableness check. If passableness of a line is not broken, replace a regulator of pressure of fuel (Section Check of serviceability and replacement of a regulator of pressure of fuel).

Check of a condition of the fuel pump

 PERFORMANCE ORDER

    In case of occurrence of problems with functioning of the fuel pump first of all check up the fact of its inclusion (item 1 see). If the pump does not join, (sounds are absent), pass to performance of procedures of following point. Disunite an electric socket of the fuel pump and directly connect to its plugs pressure of the battery (see an illustration more low). The pump should join.
    By means of wires from the complete set for start of the car from an auxiliary source connect the positive plug of the battery to the plug of an oranzhevo-black wire of a socket of the pump, and the negative plug - to the plug of a black wire of a socket and listen to the sounds speaking about inclusion of the pump (the model with the engine in volume 5.2 is shown).
    Make sure available pressure of the battery on plugs of a feeding half of socket of the pump at the included ignition (a key of position ON). If pressure is present, replace the pump (Section Cleaning and repair of a fuel tank - the general information). If pressure is not present, check up a condition of the main relays.

Check of the main relays

For full check of the fuel pump pump relays should be checked up as the relay of automatic switching-off of giving of fuel (ASD), and. Checks of both relays are made under the similar scheme.

The scheme of an electric chain of system of injection of fuel of models 1995 вып., equipped the engine in volume of 5.2 l (the scheme of other models is similar)


 PERFORMANCE ORDER

    For relay check, take it from the nest in an impellent compartment.
    Find relay ASD (marksman) and the relay of the fuel pump in an impellent compartment.
    Take the relay from the nest and make sure available pressure of the battery on nest plugs at the included ignition.
    Check up presence of pressure of a food on plugs of a nest of relay ASD.
    If pressure is absent, check up a pump safety lock. If pressure is absent and on a safety lock, check up a condition of an electric contour of the pump. Connect positive probe an ohmmeter to the plug 86, and negative - to the plug 85 and measure resistance. It should equal approximately 75 Ohm.
    Measure resistance between plugs 86 and 85; it should equal approximately 75 Ohm.
    Connect positive probe an ohmmeter to the plug 30, and negative - to the plug 87А and again measure resistance. The ohmmeter should show conductivity (zero resistance).
    Also measure resistance between plugs 30 and 87А; conductivity should take place.
    Connect positive probe an ohmmeter to the plug 30, and negative - the plug 87. Conductivity should be absent. Submit pressure of the battery on the plug 86 and earth the plug 85. Whether check up takes thus a place conductivity between plugs 87 and 30. If is not present, replace the relay.