Engines of vehicles with an injection power system are among the first to be launched by the Zavolzhsky Engine Plant (ZMZ). The four-cylinder engine ZMZ 405 is a successful representative of this category; it is installed on the Gazelle car. Replacing the fuel pump on time allows the engine to work efficiently and reliably for a long time.
More than 16 years have passed since this engine was first installed on a car. The manufacturer positions it as an engine for small trucks and buses, it is installed on such cars - “Gazelle”, “Sable”, etc. The motor works unpretentiously, it perceives road difficulties confidently. The unit is simple and the replacement of the gas pump on the Gazelle 405 can be done independently by the driver with minimal experience in an ordinary garage. The same can be said about the repair of the fuel system.
Fuel system
The Gazelle automobile system consists of mechanisms and devices interacting with each other to provide a drive. It includes:
- fuel tank;
- carburetor;
- coarse and fine filter;
- gas pump.
The capacity of the fuel tank is 64 liters. The filling hole is located on the port side and is connected to the tank using a rubber tube. At the entrance to the hole, inside there is a check valve that does not allow fuel to leak. The tank is fixed with clamps and brackets to the side members. When installing the clamps, cardboard gaskets are made between them and the walls of the tank.
The neck closes with a stopper. The space in the tank above the fuel surface with a two-way valve is connected to the atmosphere, which lets air through as the liquid level decreases or relieves pressure if the ambient temperature becomes higher. The valve is mounted on the neck of the tank and connected to the ventilation fitting using a plastic tube. The fitting is screwed onto the top of the tank.
The fuel system module of cars is installed in the tank, easily replacing the gas pump. The Gazelle minibus combines the module with a fuel level indicator. The fuel fluid comes from the fuel tank, passes through the filter screen, which is installed on the fuel pump.
Fuel pipelines are made of brass. The tubes interact with the tank, sump filter, gasoline pump, fine filter. For connection use union nuts, coupling collars, conic couplings and unions. The pipeline for draining residual fuel from the carburetor improves the functioning of the power system and allows you to start a heated engine in hot weather.
An aluminum fuel rail is needed to transfer fuel fluid to the nozzles and is attached to the inlet pipe with two bolts. The brass fitting is connected to the fuel supply pipe, mounted in front of the ramp.
The role of the gas pump
The injection of fuel fluid and the determination of the amount of gasoline entering the heating system depend on the normal operation of this small device. In modern Gazelle cars, the replacement of a gasoline pump, which is an electrical device, occurs after the upper protective cover is removed.
The gasoline pump is used to provide low pressure by pumping fuel with a manual lever. If the pump is a diaphragm type, then gasoline is supplied to the carburetor (K-) through the fuel channels. The gasoline pump contributes to an uninterrupted supply of fuel to the carburetor in outdoor conditions from + 50º to -40º, which allows its efficient operation in various temperature zones. If the supply of gasoline is interrupted, then a replacement gasoline pump is made. "Gazelle" 406, the carburetor of which suffers from a faulty device, is put into the workshop for repair.
The gasoline pump is fastened with nuts through the gasket, pulling is done evenly from all sides. If gasoline leaks along the diaphragmatic perimeter, then the operation of the gasoline pump can be considered dangerous because of the possibility of a breakdown of the pump and separation of the diaphragm.
In case of incorrect operation, it is recommended to replace the fuel pump. "Gazelle" Business is equipped with a device that turns on when a command is received from the control system and reaches a pressure of about three bar. Further, gasoline under pressure enters through the fuel pipeline, passing through the filter into the ramp.
Diaphragm fuel pump
Powered by camshaft eccentrics. Consists of separate prefabricated housing mechanisms with a drive lever and a diaphragm. The pump valve contains a cage of zinc, a rubber valve, a brass plate, which is burstable by a spring of bronze alloy. To filter the fuel, a brass strainer is installed above the pump valves.
If the engine is not turned on, you can fill the carburetor with fuel using the hand lever. To prevent the ingress of gasoline, the device is equipped with a strainer. If the fuel stops pumping, the gas pump is replaced. The Gazelle Business 4216 type with a carburetor assumes an easy replacement, since the device is located outside the fuel tank.
Fuel filter sump
It is installed on the left side of the machine and serves to clean gasoline from mechanical debris and water. Filtered sludge is collected in the lower drain box. A set of thin metal plates is used as a filter element.
Fine fuel filter
It is placed in front of the carburetor on the motor and contains in the housing design of a rubber sealing sleeve, gaskets, a ceramic filter or thick paper, a sump in the form of a glass, a spring and fasteners.
In order to limit the exhaust of toxic gases into the surrounding atmosphere, a gas recirculation system is installed on the vehicle. Part of the exhaust gas is recycled by entering from the outlet into the engine. Recirculation of working gas occurs when the engine is heated to a temperature of up to 40 ° C at partial overloads.
Gas pump location
The gas pump of the Gazelle car with a motor injector is not installed separately, but in the form of a side in the gas tank. This arrangement successfully combines the operation of devices and increases the efficiency of individual elements of the block. The gasoline pump, remaining immediately behind the filter, draws fuel directly through the pump screen, increasing the degree of fuel purification. Installation and maintenance of the fuel level sensor become more comfortable, as the wires to the gas tank and to the pump pass in one place.
The key to high-quality operation of the fuel system is the perfectly functioning Gazelle gasoline pump. Installation 402 of the system will allow fuel to be supplied in the prescribed volume at a specific time.
Troubleshooting and repair
Damage to the pump or its defective operation leads to malfunctions of the engine or other systems and components. The operational state of the Gazelle car depends on the prompt completion of the repair. Replacing a gas pump is an effective way to repair a car.
To determine whether it is worth changing the pump, or just repairing it, they diagnose the operation of the device and identify malfunctions. The most common symptom of malfunctioning is intermittent motor operation and jerking. Another sign is the long time of the plant, with the standard speed of starting work from a half turn. This sign will indicate a deterioration in work and the fact that the gas pump will soon fail, although it is still able to work for a certain time.
If you do not pay attention to such "bells" and continue to operate the car, then one day the car may not start. The cause of the inoperative condition is the pressure drop in the fuel system, and it is the faulty pump that affects it.
Instrumental testing of a gasoline pump is performed using an indicator sold in a specialized store. To find out whether the gas pump is to blame for the pressure drop or if the pressure regulator, nozzles or other devices do not work, install an indicator on the gas pump. Mounting the device is done in accordance with the attached instructions, the engine is turned off and wait about 10 minutes. If after this a significant decrease in pressure is detected, then the fuel pump is working.
Troubleshooting a gas pump using a pressure gauge
With the help of this device, it is established whether a replacement gasoline pump is needed. "Gazelle" is checked for pressure changes in the fuel network. The help of specialists is not required in this case either. The pressure gauge is connected to the nozzle frame and fastened in such a position that the readings can be seen from the passenger compartment. When the ignition is switched on, the pressure gauge works and shows the pressure created by the pump. Pressure from 310 to 380 kPa is considered normal. The verification does not end there, they pass along the road in third gear. Pay attention to pressure changes. The norm is considered, if the pressure remains normal, the fuel pump does not need to be repaired.
In another case, the car stalls, the problem is electricity. The check consists in connecting the control lamp to the relay with the ignition on. After that, it lights up for a few seconds. Leak is detected at low pressure. If the cause of the inoperative state of the machine is a fuel leak, then a gasoline pump is replaced. The Gazelle Farmer will be put up for repair in the workshop.
Before determining whether a replacement gasoline pump is needed, the Gazelle 406 is checked for the correct operation of the filtration system. Fuel filters are placed in the engine compartment or near the gas tank. To filter the incoming fuel, a special mesh is provided inside the housing. Before replacing the filter, remove the fuel pump from the tank, if it is a submersible pump.
Filter Contamination Detection
The mesh is removed, after removing the cover, if it is dirty, then it is cleaned and washed. If the mesh is badly worn, it is changed. Electric pumps are structurally more complex, they are used in the Gazelle car. Replacing the gas pump and filter in the tank is sometimes done at the same time. To do this, buy a special repair kit.
A dirty filter gives jerks when the vehicle speeds up, causing a reduction in engine power. The inability of the grid to pass fuel affects the operation of the electric motor, which operates with increased loads. As a result, plastic parts fail, moving parts wear out. Determine the clogging of the grid, listening to the sounds of the gas pump. Compared to the standard state, it makes additional sounds and noise. Before the gas pump is replaced, the Gazelle is completely de-energized, the engine power supply system is turned off.
Filter Element Selection
The main problem is the lack of initial experience and basic knowledge for the repair of a Gazelle car. Replacing the gas pump and filter is much more efficient on their own, as authorized dealers in specialized workshops sometimes change the filter element, while not paying proper attention to cleaning the separator flask.
The problem of a damaged filter is the wear of the center of the nozzle and the drain of fuel in the opposite direction. The nozzle is washed off by particles of pollution coming under high pressure, the phenomenon resembles the operation of a sandblasting apparatus. If you use poor quality filter elements, then with poor care you will have to change the fuel system, which is an expensive repair. Some low-quality filters are equipped with weak rings that fall off or hang out, because of this, untreated fuel is sucked. Sometimes new poor quality grids do not provide the required degree of gasoline filtration or have a sparse structure.
In order to distinguish a good filter from a poor-quality one, look at the junction of the filter. It should be visible strip of pink. This can be an active substance for gluing or an element showing the pour point, in any case, this sign indicates that the filter is checked for quality in the factory.
Filter Element Replacement Procedure
Before starting work, turn off the fuel heater with a wrench and disconnect the line fitting. Unscrewing the small valve at the bottom of the tank, drain the gas from the separator flask. After that, disconnect the fuel heating connector in the separator of the Gazelle car. Replacing a gasoline pump, a photo of which, like a filter, can be seen in the catalog, is done independently, without the involvement of a specialist.
Having screwed on the threaded cover, pull out the filter. It may be fully or partially contaminated. Inspect the separator flask, at the bottom of which you can find large and small particles of contamination. To remove them, use a lint-free cloth and tweezers.
A new filter is set until a slight click is heard. About a liter of cooked diesel fuel is poured into the separator so that there are no problems with pumping the system. Before putting on the separator cover, a new rubber ring is treated with oil. This will help to easily insert the cover with a slight pressure and tighten it until it stops.
Pumped fuel, the procedure is a few pressures on the button until it ceases to succumb. If previously diesel fuel was not poured into the flask, then press for several minutes to fully pump. Check the operation of the machine factory. Sometimes the motor immediately runs smoothly, but there are cases of small interruptions until excess air leaves the system.
In conclusion, it should be noted that the repair and replacement of the gas pipe and filter should be carried out in a timely manner, too many subtleties of the engine depend on the proper operation of these devices.