For the engine to produce the necessary torque, it needs fuel. Its supply is made by a special pump. But sometimes it happens that he fails. How to check the operation of the fuel pump with your own hands? Let's consider.
Characteristic
The fuel pump serves to supply fluid from the tank to the nozzles. It works under high pressure. Then the liquid is mixed with air and a fuel-air mixture is formed. If the element is defective, the fuel supply will stop. To maintain pressure, the pump has a special gearbox.
About varieties
Depending on the type of fuel system, there are several varieties of these elements. So, on carburetor cars use a mechanical pump. On the injection, it is submersible and driven by an electrician. Inside the element there is a special motor and pump. If one of these elements fails, the entire fuel pump stops working.
How to check without dismantling? Signs
There are several symptoms by which you can determine the malfunction of this node:
- Jerks while driving.
- Difficult start of the car.
- Deterioration of dynamics of dispersal. The machine is slowly gaining speed, even if the trigger is fully pressed.
Also note that similar symptoms can occur with malfunctions in the mass flow rate sensor or the throttle position. It will not be superfluous to check and replace the filter, both gasoline and air. The last resource is 10 thousand kilometers. You can determine its wear visually.
If it is in this condition, it must be urgently replaced. As for
fuel filters, they are manufactured in an opaque case. Therefore, it is required to write down the replacement schedule. On gasoline cars, it changes every 50 thousand kilometers. On diesel - every 10 thousand (fine cleaning).
Fuse and relay
Both elements can affect the fuel pump. How to check it? It is enough to remove the fuse cover.
See if there are any burned items. On the wing there is a circuit where it is indicated which fuse is responsible for a particular electrical device. As for the relay, it can be located under the glove compartment, or in the engine compartment. How to check the fuel pump relay? Everything is very simple. To do this, you need an assistant who will turn on the ignition at your command. At this time, you feel the relay with your hand.
It should click. If not, most likely, it fell into disrepair. It also happens that the part does not work due to poor contact. Clean the terminals and check again. If this does not help, replace the relay.
The relay works, but the pump does not pump
If the item is in order, it is necessary to diagnose the voltage at the fuel pump. To do this, use a multimeter. Check if voltage is supplied to the fuse. Often an open circuit is located in this place. Also check the voltage on the wires of the gas pump themselves. If the mass goes away, the multimeter shows values below 12 V.
The wires or terminals may have oxidized. You can clean them with sandpaper or solvent.
We call the relay
If the car starts to stall on the go, the reason is the electrical part, namely the relay. We connect a control light to it, and the second end - to the fuel pump. Turn on the ignition. If it lights up for several seconds and goes out, a short circuit has occurred in the circuit or one of the wires is disconnected.
How to check the pressure of the fuel pump? Ways
It happens that the element works, but does not give the right pressure. In injection systems, nozzles are very demanding on this indicator. Due to low pressure, difficulties may occur with starting the motor, and dips in dynamics. How to check the fuel pump? There are several ways to do this. The first is a service station check. The price of such a service is about 300 rubles. However, you can check the pressure yourself. Now there are special pressure gauges for the pump on sale. But their cost reaches two thousand rubles. You can use the ordinary one, which goes for car wheels. Each motorist has such a pressure gauge.
Self diagnosis
The pressure level that the pump reproduces is 6 atmospheres. Therefore, it is important to achieve tightness of joints.
For sealing, you need a fum tape and a nozzle with a diameter of 9 millimeters. So, how to check the pressure of the fuel pump with your own hands? Open the hood and look for the ramp with nozzles. Usually it is covered with a plastic casing. We remove it and see the cap in the form of a wheel nipple. Turn off part of the ramp. Be careful - gasoline can spill under high pressure. How to relieve pressure? To do this, remove the fuse on the fuel pump and start the engine. After a few seconds of operation, it will die out. There will no longer be fuel in the system from the pump to the injectors. You can safely unscrew the ramp that goes to the fuel pump. How to check further? We put on a hose with our pressure gauge, seal it with a fum tape and fix it with a metal clamp for reliability.
Next, the assistant turns on the ignition. You are looking at the pressure gauge at this moment. If the obtained values are below five atmospheres, then the element is not capable of generating the desired pressure.
What's next
Low pressure can occur due to a damaged diaphragm of the pump or a loose connection to the stem. To restore the serviceability of the element, it is necessary to disassemble the upper part of the housing and tighten the fastenings of the diaphragm, or replace it with a part from the repair kit. If there is a leak between the components of the mechanism, tighten the connecting screws and replace the gasket. The latter also comes in the repair kit.
Replace with a new one or not
If the malfunction concerns the mechanical part, the motorist has two ways to solve the problem. The first is the purchase of a repair kit. It includes all the necessary parts that may break in the pump. The second is the replacement of the whole element with a new one. This is a more reliable and reliable way. But it is worth considering that submersible pumps are very expensive. Among the manufacturers on the market there are both originals and analogues.
Specialists advise buying Bosch and Masuma pumps. The performance of these elements is 130 liters per hour. This is quite enough for cars, as well as for minibuses and frame SUVs. Price - in the region of two and a half thousand rubles. Also, when replacing the pump, a new fuel filter is installed. Among the good manufacturers, we note the company Mann. When replacing the filter, pay attention to the arrow. It indicates the direction of the fuel. If mixed up, all the dirt from the tank will enter the nozzles.
Conclusion
So, we found out what a fuel pump is, how to check it with our own hands. As you can see, problems can concern not only the electrical, but also the mechanical part. When repairing or replacing a pump, it is not always possible to resume the serviceability of the fuel system. The reason may be commonplace - a blown fuse, or oxidized contacts on the relay.