10.3.4.4. Control of pressure of supply of fuel
Purpose of this control: check of tightness of connections of system of fuel feeding, check of operation of the regulator of pressure and check of work of an electrogasoline pump.
Take off pressure in system of fuel feeding as above for removal of the unit of the central injection is described.
Connect electrical wires to an electrogasoline pump. Disconnect a fuel-supply line from the bringing union of the unit of the central injection and connect through a tee the manometer between the union and a fuel-supply line.
Put the ignition key in position "Ignition", check tightness of connection of the manometer and its indication. Pressure has to be within 190–210 kPa. If there is no pressure whether check for hearing the electrogasoline pump at turn of the ignition key joins in situation "Ignition" (operation of the pump and clicks of operation of its relay can be heard being in interior of the car).
If the electrogasoline pump does not join, check of electric chains of the pump is necessary.
After two seconds of work the electrogasoline pump has to be switched off as at the idle engine basic signals of provision of a bent shaft do not come to an electronic control unit. Again to turn on the pump, it is necessary to switch off ignition for ten seconds and to include again.
After an electrogasoline pump stop pressure can go down and be stabilized a little or on the contrary — to increase if the engine is heated-up. If pressure is not stabilized and goes down, include an electrogasoline pump and right after its stop press a fuel supply hose in the unit of the central injection.
If at the same time pressure does not fall, then check tightness of fuel-supply lines from a tank to the unit of the central injection, and also the filter of thin purification of fuel, then repeat check of pressure in a fuel supply system.
The lowered pressure (lower than 190 kPa) can be caused by malfunction of the regulator of pressure of fuel or restriction of capacity of a fuel supply system.
On discharge it is possible to determine the capacity of system of fuel feeding by fuel consumption. If necessary replace the filter of thin purification of fuel new.
Operation of the regulator of pressure can be checked according to indications of the manometer for what disconnect a drain hose and lower in the prepared capacity. Include an electrogasoline pump, press a drain hose and check pressure which can create the pump on the manometer. Release a hose. The manometer will show pressure of operation of the valve of the regulator. If necessary replace pressure regulator.
Elevated pressure in system of fuel feeding (over 210 kPa) can be caused by malfunction of the regulator of pressure of fuel or the increased resistance to discharge of fuel in a tank. For check connect the manometer to system of fuel feeding, disconnect a drain hose in a motor compartment and lower in capacity. Include an electrogasoline pump and according to indications of the manometer check pressure in system.
If pressure is higher than norm, replace the fuel pressure regulator. If it does not help, then find and remove the cause of the increased resistance to fuel discharge.