The fuel pump Gazelle: repair and maintenance

Zavolzhsky motor plant – the main supplier of engines for cars “Volga” and “Gazelle". The motors of this company has long been known to the Russian public and techniques-minders. Good maintainability, ease of construction and reliability of the main systems rightly put these engines are among the best domestic motors. Moreover, in the late 90-ies of XX century the plant was designed and installed on these engines the injection system. These motors, in particular, ZMZ-405, mounted on light-duty trucks "Gazelle" vans "Sable" and their modifications.

Of Course, the injection system is complicated work and repair, but maintenance of the engines do not cause special questions. The same can be said about the repair of fuel systems of cars ‘Gazelle” and “Sable”.

Device power

Her pattern for almost all engines with fuel injection system are structurally the same. It is composed of tank module, pump, lines, rail and injectors. To support include a ventilation system of the gas tank, return flow fuel, fuel gauge. In the carburetor system of the scheme excluded the rail with the injectors and added the carb. The power supply system also has a system of back flow of fuel in the tank when the engine is not running.

Location of the fuel pump ‘gazelles’

The Fundamental difference between a carbureted and a fuel injected system is in the location of the pump. On the carburettor unit, it is on the engine. The unit is equipped with a mechanical drive from the camshaft. On a fuel injected modification element is installed directly in the tank and has an electric drive. How is powered the fuel pump ‘gazelles"? Connection to the electrical system performed along with switching of the fuel level sensor. The design presented in the form of a pair of connectors that are on the tank. The pump system creates a significant pressure so the fuel comes to the injectors at high speed. This part of the process of fuel injection. So the fuel better mixed with air before it enters the cylinders.

Device pump

Diaphragm element on carbureted models pumping gasoline at the expense of rarefaction created a special petrol-resistant diaphragm. On fuel injected motors, as mentioned above, the pump is installed directly in the tank. Element is connected with the strainer and fuel level sensor. Structurally, it is a vibrating pump, in which a moving anchor to pump fuel. This option is considered much more reliable as it does not suffer from the main disadvantage of gasoline pumps gasoline engines – overheating in hot weather and reduce the performance. It is high-quality and stable operation of the element is the basis for proper operation of the engine, which is completely dependent on the amount and brand mixtures.

Features filters

Cleaning the fuel that enters the engine is through two elements. The first (cleaner tank) is located near the gas tank. He holds a major dust, dirt and water, which is collected in a removable Cup at the bottom. Fine filter is installed in the gap of the hose to the carburetor. It is designed to delay the smaller particles of dirt: the fuel passes through a special cardboard, enclosed in a plastic cylinder.

On fuel injected engines clean fuel through a filter located at the intake ports of the pump. It is a thin flat metal mesh. It effectively holds in itself the dirt and debris trapped in the tank.

Troubleshooting

So, what to do if not working the fuel pump? "Gazelle" in this case needs to be diagnosis. It should be noted that the most common problem – there is insufficient fuel pressure. It is very harmful to the fuel injectors. For this reason, they fail. The first sign of failure – jerks while driving. The reasons for this can be as low fuel rail pressure, and irregular operation of the pump. Another alarming manifestation – hard starting of the engine. Fuel injected engines are easy starting. In case of interruptions in operation of the fuel pump motor start up with the second or third attempt. It is not good. Verify the fuel pump“the Gazelle 405” by using a special indicator for a fuel injected engine. The very diagnosis is quite simple – everything stated in the instructions to the indicator. At malfunction of the electric circuit the engine will not start. To start searching for the problem with checking fuses, relays and wiring.

The Differences are diagnostic of diaphragm element

As carbureted fuel pump "Gazelle" ZMZ-402 has a mechanical drive, the electric component is not there. Failure of this type of pump usually leads to rupture or damage the diaphragm. Because of this reduced fluid pressure in the worst case, its flow stops completely. Diaphragm replacement is not much of a problem.

Check fuel pump with pressure gauge

Also check the operation and performance of mechanism by using a special gauge. It connects to the fuel rail and measure the pressure created by the pump in the system. When you turn the ignition from start to run fuel pump. "Gazelle" make do not have. The pressure gauge will read pressure. Ideally, it should be 300-380 kPa. After that you must disconnect the gauge and ride on a regular road with acceleration and braking – standard test drive. Then again measure the pressure. If it is different from initial measurements, the mechanism is faulty, or the resource is close to completion. Can it be retrieved? Will talk about it below.

Repair pump "Gazelle"

For gasoline engines the fuel pump is removed simply. To do this, detach the fuel hoses, unscrewed the nuts holding the flange of the pump to the cylinder head. In addition, for repair do not have to dismantle the whole mechanism. To replace the diaphragm, it is sufficient to remove only the top hemispherical portion. Repair pump "Gazelle" the injection system is impossible - it is subject to change. To remove the element you want to remove the flange ring from the gas tank to reduce the pressure in the fuel system, disconnect the leads and remove the Cup together with the fuel level sensor. It looks as follows:

The Pump rests on the latch and is removed from the housing together with the filter that it is wise also to replace. On sale is a complete set consisting of a submerged filter and the fuel level sensor and a separate fuel pump. On the "Gazelle" price is 1-2 thousand rubles. Full set – up to 4 thousand. As for the element for carbureted models, the price of it in the collection is around 1 thousand rubles.

Conclusion

Diagnose and repair fuel pump "Gazelle" is a simple job that almost any enthusiast who understands the principles of operation and characteristics of the device. To replace requires a minimum set of tools.