Electric fuel pumps - examination

Electric fuel pump

In automobile systems where gasoline is supplied by injectors, pressure is needed. The use of old pumps, the design of which involves a completely mechanical principle, is unacceptable in modern cars. For this reason, the injectors use only an electric pump that pumps gasoline directly from the fuel tank, which ensures the injection of a jet of fuel into all parts of the power system.

What happened?

The performance range was from 67.1 to 146.7 l/h - more than double!

The lowest performance was found in an expensive pump costing 3,250 rubles. Let us remind you that we bought the cheapest one for only 900 rubles.

Details are in the final table.

Of all the results obtained, we consider the main ones to be the pressure regulator opening voltage, as well as the pump efficiency - the ratio of performance to power consumption. We recalculated these values into ratings on a five-point scale: more is better. Their arithmetic average allows us to judge the technical perfection of the pump.

The best were the Italian ERA Fuel pump and the Chinese Kortex KPF. It is curious that both were sold as “foreign” ones: the first for Mitsubishi, the second for Mazda.

But the worst in all respects was... Bosch.

The real characteristics of the tested pumps are not proportional to the price tags, so in conclusion we calculated the price/quality ratio, also bringing it to a five-point rating system.

Surprisingly, the leader was not a frankly cheap pump, but... the same Italian EPA. Absolute victory!

The components of an electric fuel pump, which we tried to artificially overheat by screwing a self-tapping screw into the gap between the blades of the impeller and holding it in a braked state under voltage for five whole minutes. The body heated up to 60 °C, smoke appeared, but the motor did not fail - and even started working after the “load” was removed! Having disassembled the fuel pump, we did not find any melted or damaged elements. This proves that it is even difficult to kill an electric fuel pump. This is one of the most reliable units of a modern car.

Types of electric fuel pumps

Today, the following types of electric pumps are distinguished.

The gear pump operates by eccentric movement. Installed in the fuel line. The pump is equipped with two internal gears, which pump gasoline when rotating.
Rotary roller. This type of pump is also installed in the fuel line. Its design includes an electric motor, on the rotor of which a disk with rollers is installed. A part of this type has two outlets: one for fuel to enter inside, the other for its exit.
Turbine or centrifugal. This is the most popular type of pump, installed directly into the car tank. The fuel wire is connected to it already inside.

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A submersible or turbine pump is used in most modern foreign cars. It is located in the tank, which minimizes fuel losses and better protects the pump from damage. In addition, the pump inside the tank is cooled better and does not overheat even after very long operation.

Vin submersible fuel pump

Cooling is carried out by flushing the pump housing with fuel. Thanks to this, a significant part of the heat is removed. It is for this reason that the recommendations for cars with submersible pumps prohibit driving with a half-empty tank, because this negatively affects the life of the fuel pump.

Model selection

It is best to install an imported fuel pump on the VAZ 2110 injector, capable of delivering a performance of up to 7 atm. It will not only last much longer, but will also ensure better and longer operation of the injector and improve the quality of the mixture at the outlet of the nozzle.

You should know that Bosch fuel pumps usually differ only in length, location of terminal connectors, and sometimes in the diameter of the housing. Therefore, it is advisable to either go shopping with an old device, or make some minor modifications at home.

Bosch fuel pump

To avoid buying a fake, keep in mind that any Bosch gas pump is packaged in very durable packaging. The bag contains purified gasoline in which the device is immersed. If you smell it, it means the seal is broken, corrosion may begin inside the pump, it’s better not to buy one.

You can get acquainted with the malfunctions of the VAZ 2110 fuel pump here:

The process of replacing a fuel pump on a VAZ-2112

General view of the fuel pump module

The gasoline pump on the VAZ-2112 is located in the fuel tank.

The type of part is called submersible. Therefore, to replace it you will need to pull it out from the gas tank. It contains the FLS (fuel level sensor), which transmits readings.

Disconnect the battery.
Removing the battery terminal for repair
We are dismantling the rear sofa.
Pull the loop to remove the rear sofa
Unscrew the two screws securing the top plate.
Remove the hatch cover.
Unscrew the fastening screws and remove the fuel pump hatch cover.
Disconnect the power connectors on the fuel pump.
Disconnect the power cable connector
Using a 17 wrench, unscrew the fuel supply pipes.
Unscrew the fuel supply pipes
Now, release the pressure ring and dismantle it.
Remove the sealing ring
We carefully lift the fuel pump and remove the float from the tank cavity.
Remove the fuel pump from the tank
We dismantle the gasoline pump.
We change the rubber o-ring, which is located on the lower seat.
We carry out the assembly in the reverse order.

Now the gasoline pump has been replaced and you can continue driving. The average service life of a new product is 150,000 km.

Reasons for fuel pump failure

So, let's look at the main ones:

Low-quality fuel leads to clogging and failure of the mechanical parts of the gasoline pump.
Wear of internal parts of the fuel pump.
The appearance of scuffs and shells, which occur mainly in winter, when the water in gasoline turns into ice.
In the summer, when the heat is intense, gasoline loses its lubricating properties, which can lead to failure.

Choice

The choice of an electric fuel pump should be approached responsibly, because if it fails on the road, the car will not be able to continue driving. When assembled, this part has the article number - 2112-1139010

. It is used both for the original product produced by AvtoVAZ and for analogues.

The second most popular manufacturer is Pekar

, which has been producing fairly reliable spare parts for VAZ family cars for many years.
The pricing policy for electric submersible gasoline pumps of the 10th-12th generation fluctuates around 1,200 rubles.

Principle of operation

The electrical circuit needs to be constantly checked, because if one of its contacts is broken, the fuel pump will start to work incorrectly, so the operating principle will change.

Actually, during normal operation of the fuel pump, the following main stages occur:

Fuel is supplied to the filter through the fuel pump. In a VAZ 2110 car, this filter can be located both inside the pump and on the fuel line;
After this, the fuel passes into the fuel rail, where it is supplied under pressure to the injectors;
The electrical circuit of the fuel pump is designed in such a way that if any excess fuel remains, it is cut off by the pressure regulator and then drained back into the gas tank;
The computer device gives a pulse that opens the injectors at the right moment, after which fuel is supplied through the fuel pump.

How does a fuel pump work?

Despite the fact that all fuel pumps perform the same task (deliver fuel to the engine), they do it differently. For example, with high or low pressure, directly into the injectors or into the carburetor chamber. Modules and structures differ, and electrical devices are especially diverse. Mechanical ones in this regard are among the simplest. Here are the features of each of them:

Mechanical carburetor fuel pump

Designed to supply fuel from the tank to the carburetor float chamber. The most common option is diaphragm. It is driven by a camshaft eccentric (sometimes an oil pump shaft) and is mounted on the side of the engine. The advantages of such a mechanism are the simplicity and reliability of the design. If necessary, fuel can be pumped into the chamber manually. A significant disadvantage of mechanical fuel pumps is that they cannot create the pressure that is necessary for the injector of modern cars.

How to Test a Mechanical Fuel Pump

To check a mechanical fuel pump, you will need the following tools and tools:

slotted screwdriver;
key (head) 10;
key to 13;
2 clean dry plastic bottles with a volume of 2 liters;
a piece of hose (50 cm) of the same diameter as the fuel one;
1–1.5 liters of gasoline;
caliper (ruler);
stopwatch (clock).

Let's start with performance. A working VAZ 2110 mechanical fuel pump with a obviously clean filter should pump at least 1 liter of fuel per minute. The verification algorithm is as follows:

If the amount of fuel pumped per minute is less than a liter, the pump is faulty. The reasons for this may be:

faulty valves;
rupture of one or more membranes;
clogging of the pump grid;
wear of the drive rod (pusher).

We carry out further checks in the following order:

Disconnect both fuel line hoses from the pump.
Disconnect the inlet and outlet hoses
Checking the intake valve. To do this, plug the corresponding fitting with your finger and press the manual fuel pump lever several times. You should feel the vacuum (suction) with your finger. If it is not there, the valve has failed.
Checking the exhaust valve.
Place your finger on the outlet fitting and press the lever. The air pressure should be felt at the outlet. Otherwise, the exhaust valve is faulty. When you press the manual pumping lever, you should feel a vacuum at the inlet fitting, and a pressure of air at the outlet
If everything is in order with the valves, check the condition of the filter mesh.
Using a 10mm wrench, unscrew the pump cover. We remove it from there and inspect the mesh for clogging. The grid is fine - let's move on. The mesh filter should not show signs of damage or deformation
Using a 13mm wrench, unscrew the pump mounting nuts.
Carefully, so as not to damage the gaskets, remove the device from the studs, drain the gasoline from it, and remove the pusher.
Unscrew the two nuts and remove the fuel pump from the studs.
Using a slotted screwdriver, unscrew the 6 screws connecting the 2 parts of the pump housing.
We disassemble the device, remove the rod with membranes. Unscrew the top nut with a 10mm wrench and remove the membranes from the rod. We assess their condition. They should not have cracks, breaks, or signs of deformation. To disassemble the pump you need to unscrew 6 screws around the circumference of the housing.
Using a caliper or ruler, measure the length of the fuel pump drive rod.
It should be 82.4 mm. If it is less, or the rod has signs of wear on any of its ends, it is unsuitable for further work. The length of the pusher should be 82.4 mm

Checking the fuel rail pressure

But even the fact that the fuel pump starts pumping when the ignition is turned on does not mean that it is working properly. The main indicator of its operation is the pressure in the system. You can check it using a regular pressure gauge with a measurement limit of 5–7 atmospheres, which is used to measure tire pressure. In addition, you will need a piece of gas-resistant hose with an internal diameter of 9 mm and two clamps of the appropriate size.

The verification procedure is as follows:

We relieve the pressure in the system. To do this, disconnect the negative terminal from the battery. We remove the plastic lining of the additional mounting block, which contains the relay and fuse for the gasoline pump. We remove the fuse from the socket. Connect the removed terminal to the battery. We start the engine and let it run until it stalls. After that we put the fuse in place.
On the fuel rail we find a fitting specially designed for measuring pressure. Using the wheel valve cap, unscrew the spool valve from the fitting.

The fitting is designed specifically for measuring pressure

We put one end of the hose on the fitting and secure it with a clamp. We connect the second end to the pressure gauge and also secure it with a clamp.
Turn on the ignition and wait for the pump to pump fuel into the system.
We look at the pressure gauge readings.

A regular tire pressure gauge is suitable for measuring fuel pressure in the rail.

For engines with a volume of 1500 cm3 it should be 2.8–3.2 atmospheres, and for power units with a volume of 1600 cm3 – 3.6–4 atmospheres. If the device indicators are lower, the pump is unsuitable for further use.

Which fuel pump to choose for replacement

BOSCH fuel pump 580454138 is installed from the factory.

. Its service life depends on the quality of the fuel used, as well as on operating conditions. It is also worth noting that this pump is suitable for most other cars, including imported ones. The cost of a BOSCH fuel pump at the moment is from 1,700 rubles. Cheaper analogues are also offered on the market:

WEBER FP 453-453 from 600 RUR
ATS 2112-1139010 from 550 RUR
PEKAR 2112-1139010 from 600 RUR
FENOX EFP35005O7 from 700 RUR
HOFER HF 830 301 from 550 RUR
StartVOLT SFP 0153 from 750 RUR
VOLTON VLT2112-1139010 from 650 RUR

Any of the above fuel pumps will be suitable as a replacement for the original one, however, not all of them are of the same quality as the original. In addition to the pump itself, you may need a corrugation to replace it, and if the fuel pump mounting ring is damaged, you can order it or purchase it using the following article number:

Electric fuel pump ring /2110/ metal price from 120 rub.
Fuel pump corrugation /2110/ 1.5 white from 50 rubles per piece
Fuel pump corrugation /21101/ 1.6 long from 60 rubles per piece

If you decide to replace the entire fuel module assembly, you can select one of the suggested modules below.

Electric fuel pump module /21101/ V=1.6 assembled PEKAR price from 2500 rub.
Electric fuel pump module /21101/ V=1.6 assembled “UTES” price from 3200 rub.
Electric fuel pump module /21102/ V=1.5 assembled “UTES” price from 3000 rub.
Electric/fuel pump module /21102/ V=1.5 assembled HOFER price from 2000 RUR

If you decide to change only the fuel pump, we recommend that when replacing it, you immediately carry out a complete inspection of the module - check the check valve and both corrugations, and also, if necessary, replace the fuel grid.