How to Flush a Trimmer Fuel System

Periodic flushing of the engine fuel system is necessary for all vehicles. The chemical composition of gasoline contains elements that, during combustion, settle on the walls of the fuel pipe and nozzles, reducing the efficiency of the unit and increasing fuel consumption. If for some reason we cannot or do not want to seek help from a service station, the only thing left is to flush the fuel system with our own hands.

Signs of fuel system contamination

First, let’s look at the signs of contamination of the fuel system. Experienced drivers can almost intuitively diagnose the condition of the engine. But what about those who bought their first car? We advise you to pay attention to the following symptoms.

How to Flush a Trimmer Fuel System

  • The car lost playfulness. The engine is inhibitedly responding to the accelerator pedal, the acceleration of the car slows down.
  • When you sharply press the gas pedal, the car “buzzes”.
  • During acceleration, “dips” are observed in acceleration.
  • The car does not start with a half-turn, there are problems with starting a cold engine.
  • Significantly (on average by 20%) increases fuel consumption.

The above features of the engine are indirect signs of contamination of the fuel system. The final conclusion can only be given by the workshop master. But even in the absence of such malfunctions in the engine, it is necessary to periodically carry out preventive cleaning of the fuel system of new cars every 5000 km of run (using additives). Older cars (with mileage from 50,000 km) require attention every 30-40 thousand km (cleaning nozzles). The fuel system of cars with a range of more than 150,000 km must be completely cleaned and then the nozzles washed every 30 thousand km.

Do-it-yourself carburetor

Litmus test, by which you can determine whether it is time to clean the carburetor, are spark plugs. If they are covered with soot and have a black color, it means that more fuel is supplied than necessary, and the carburetor needs to be cleaned.

The normal color of the candles is taupe. In this case, you can not worry: the fuel system of the car is in order.

To clean the carburetor, you will need the following tools and materials:

  • clean rags without lint;
  • rubber protective gloves;
  • a special tool for cleaning the carburetor (preferably in the form of an aerosol with a mounted thin tube that can penetrate hard-to-reach places);
  • a set of keys and screwdrivers;
  • rubber bulb;
  • protective glasses;
  • the capacity in which the carburetor parts will be rinsed (a metal basin is suitable).

And now directly about the washing process.

  1. Disconnect the manual starter and remove the engine cover to allow access to the carburetor.
  2. Remove the compression pump from the fuel line. Disconnect all wires from the carburetor.
  3. Remove the bolts holding the unit and remove it.
  4. Disassemble the carburetor for parts, having previously disconnected the casing.
  5. To avoid damage with cleaning agent, remove the float and the needle of the float valve from the carburetor. Shake the float. If at the same time you hear gurgling sounds, you will have to change it.
  6. The float chamber is cleaned with a rubber bulb, with which the remaining fuel is sucked up, after which the bottom of the chamber is cleaned with a stiff brush. In this case, in no case should you lower the carburetor cover with the float down.
  7. We clean the main air jets with compressed air. In case of severe clogging, you can use a thin copper wire.
  8. Next, you need to remove the highly productive nozzle. If it is not removable, remove the plug, otherwise the nozzle will not be flushed from the inside.
  9. Soak the carburetor parts in the container where you previously poured the cleaning agent. When handling hard-to-reach spots, use an aerosol with a nozzle tube. The duration of the soaking procedure depends on the cleaning agent you have chosen. Non-metallic parts (diaphragm, gaskets) should be washed separately using gasoline. Carburetor cleaner is not designed for plastic and may damage it.
  10. Wipe the parts with a dry cloth and allow them to dry well.
  11. Assemble the carburetor and install on the car.

We proceed to consider the following type of ICE.

Flushing the fuel system of the injection engine

Flushing the fuel system of injection internal combustion engines (ICE) can be performed in several ways.

Does not clean the gas tank and fuel line; visually, the flushing quality is not determined

Efficiency, visually determined flushing quality

Flushing algorithm for the entire system

To clean the fuel injection system with your own hands, you will need:

  • a set of keys and screwdrivers;
  • petrol;
  • spare gas pump;
  • air tank or compressor.
  1. Remove the fuel rail, on which the nozzles are located. It is better to entrust the cleaning of nozzles to professionals, they will do it better. For those who want to do this on their own, below we will tell you how to do it. The ramp is purged (use a cylinder of air) and flushed with gasoline.
  2. We clean the throttle: soot on it increases fuel consumption by 5-10%.
  3. We unscrew the old fine fuel filter (its place is under the bottom or under the hood on the fuel line) and replace it with a new one.
  4. We take out the gas pump from the tank. instead of it, it is better to put a new one. When this is not possible, it is worth replacing the filter mesh located at the entrance to the fuel pump. It is usually very clogged.
  5. When the dismantling of the fuel equipment is completed, blow all the piping through the compressor.
  6. We remove the tank and purge it using a compressor or an air cylinder.

We can begin to build and test the system.

Nozzle flushing algorithm

For those who want to wash the nozzles with their own hands, we recommend that you proceed in the following order:

  1. Prepare the necessary tools and materials. 2 spray cans of carburetor cleaner (aerosol), insulation tape, 12 V bulb, wires, 0.5 m hose (with a diameter suitable for your nozzles), doorbell button.
  2. After removing the nozzles from the ramp, inspect them and determine where the feed channel is located, and where is the sprayer (it is usually covered with a brown oily coating).
  3. If there is a strainer on the nozzles, remove it with the rubber seals.
  4. Assemble the cleaning system. After wrapping the electrical tape over the spray tube of the aerosol can, insert it into the nozzle supply channel. If this fails, use a hose as an adapter, wrapping one end of the tape to the nozzle with tape, and the other to the spray can.
  5. Make an electric circuit according to the diagram below: we connect one of the wires to the “plus” on the battery, the light bulb and “” on the nozzle terminal, the second we connect the battery minus, the doorbell button and the nozzle negative terminal.
  6. Create pressure in the nozzle by attaching the can to it as described in step 4 and pressing its valve. At the same time, press the call button. A non-uniform fuel torch should escape from the nozzle atomizer. Repeat the process until the torch becomes even.

Video: How to Flush a Trimmer Fuel System

When installing nozzles, we recommend replacing the rubber seals with new ones.

Flushing the diesel engine fuel system

When flushing a diesel engine, you will need:

  • flushing fluid for diesel engines at the rate of 1 liter per 2000 cm 3;
  • 2 fuel filters of thin cleaning for diesel ICE (not paper);
  • a clean and dry plastic bottle of 1.5-2 liters with a cut neck;
  • 3 transparent hoses of 2 m;
  • clamps;
  • screwdriver.

Flushing Instructions:

  1. Pour rinse liquid into a plastic bottle. Be careful: it is poisonous. Try not to touch it with unprotected hands and avoid getting it on the body, otherwise you will have to learn the basics of self-painting a car.
  2. We disconnect the return and feed from the high-pressure fuel pump (TNVD), instead of which we fasten the transparent hoses we prepared with clamps, lowering their second ends into a bottle with washing liquid.
  3. We start the engine. We give it to work at idle for 15 minutes, at the end we podgazovyva, wait 3 minutes at idle and turn off.
  4. We pause for 20 minutes. During this time, the deposits are acidified, and the liquid cools. Repeat the procedure several times until the cleaner is fully used.
  5. In no case do not allow the engine to stall due to lack of fluid: you must have time to turn off the engine before it is finished, otherwise the electronics may suffer.
  6. We connect the native fuel hoses and start the car. We stop the engine only after it starts to work quietly and smoothly.

This completes the flushing of the fuel system. For those who feel the potential and desire to learn other skills related to the repair and operation of the car, we will tell you how to do a complete overhaul of the engine with your own hands, protect the body from corrosion and self-level the roof.

Flushing the fuel supply system to the combustion chamber, according to manufacturers of cleaning systems, promises car owners many benefits: reducing fuel consumption, increasing engine life, improving dynamics, increasing maximum speed, reducing toxic emissions, and so on. Is everything so beautiful as we are promised?

Flushing the fuel supply system to the combustion chamber, according to manufacturers of cleaning systems, promises car owners many benefits: reducing fuel consumption, increasing engine life, improving dynamics, increasing maximum speed, reducing toxic emissions, and so on. Is everything so beautiful as we are promised?


The VAZ-21083 and 21099, equipped with 1.5-liter engines with a GM injection system, and two Volkswagen with MonoJetronic (RP engine) and KE-Jetronic (JN engine) went for a “test flush”.

“Ninety-ninth” was the youngest both in year of birth and in mileage. about 50 thousand km.
Eighty-third is a bit older. Her “life path” at the time of the operation was about 100 thousand kilometers.

VW brand was represented by two Passat 1988 release, but different models. B32 (released before 04.1988) and B35i (after 03.1988). Both run. about 200 thousand km.


Flushing of various fuel injection systems is carried out using the installation M7 Plus (recently appeared A8 Plus) manufactured by Lubrichim concern.
M7 Plus replaces the fuel tank and pump. Gas is poured into the tank and the original Autoplus cleaner is added. The engine starts. Gasoline from the car’s fuel tank is “chased” by the pump in a closed circle. through the fuel wire to the adapter, which is installed during installation of the device, from the adapter through the “return” back to the tank.

The engine runs using the M7 Plus fuel pump, which delivers the fuel mixed with the cleaning fluid to the fuel distributor at the correct pressure.

The principle of operation with diesel engines is similar.
The M7 Plus fuel tank has three fill levels. for engines with different numbers of cylinders. Flushing continues until all gasoline burns out.

For a certain time, the cleaner, using gasoline as a carrier, moves through the fuel line, fuel distributor and nozzles, washing away tarry deposits and other muck along the way. Then it enters the combustion chamber, cleans it, the upper working part of the piston and partially the compression rings. Part of the cleaner enters the inlet and outlet valves.

At the beginning of work from an “artificial heart”, VAZ and VW engines, regardless of the year of manufacture and mileage, worked hard, occasionally skipping flashes in the cylinders and losing idle speed. After some time (each car has its own), the motor operation stabilized and by the end of the process came to a norm determined by a mechanic.


All four cars reacted differently to the described procedure. “Ninety-ninth” after connecting to the fuel distributor “native” pipes started up immediately. After 50-60 km of run, its owner felt that reception was improved and the engine began to work more stable than before washing.

“Eighty-third,” as it should be spitting white smoke during the washing process, started up without any visible problems. According to the owner, in normal modes, the engine behavior has not changed much, but in the fifth gear the G8 began to accelerate very well, and the engine in this mode received confident traction from 80 km / h.

VW Passat B35i survived the process itself pretty well, but after a while various sores began to come out, mainly related to starting a cold engine. The owner claims that the car on the highway began to behave better, and the engine leveled off.

Most surprises presented VW Passat B32. Apparently, in life he got a lot more than three other cars. Starting work on a mixture of gasoline and a cleaner was painful: from time to time a large tremor passed through the engine, and clouds of white smoke flew out of the exhaust pipe. Since the car is equipped with a lambda probe and a catalytic converter, the process took place at increased speeds, as required by the instructions.

The “fever” went fast enough. But at the end of the flushing, the engine completely refused to start. After some unsuccessful attempts, it was nevertheless possible to ignite the fuel mixture in the combustion chambers, but not all and not all cylinders.

Almost all parts that could be separated from the engine and injection without complex work were twisted and studied. It turned out that almost everything that was after the intake valve was covered with a thick black soot with a shiny lacquer surface.
The next day, the car had a journey of 300 km.

Refueling the fuel tank in the morning with expensive but high-quality gasoline, the dejected B32 owner went into the dark. The city regime turned out to be painful: floating idle, jerking in the speed range from 1000 to 2200, “sticking in cotton” after 4000 and so on.

On the track, it was more or less smoothed out by a constant speed mode, although before the run of 150 km there was some tension in the engine. Then, for no apparent reason, a second wind opened. Failures disappeared, reception improved. The motor began to work noticeably quieter, and even the former noises of hydraulic lifters disappeared.

Another disassembly of the injection system and the engine for about 250 km and peering into accessible openings with the help of a flashlight showed that the fuel distributor and candles are clean, the lambda probe is worn (which is natural), but does not have the same suspicious raid.

Now the average fuel consumption (AI-92 Futura Neste) on the highway is about 6.2 liters per 100 km when driving at an average speed of about 90 km / h. Before flushing. 7.8 liters. Fuel consumption in the combined cycle decreased by about 0.8 liters.


It is worth washing the injection system, but with a few reservations.

The first. if washed, then regularly, at least once per 50 thousand kilometers.

The second. before washing, read the instructions for use of the cleaner. For most cars manufactured after 1986 and having a lambda probe and catalyst, the initial flushing stage must be carried out at a speed of at least 1800-2000, otherwise you can ruin the catalytic converter, “get” to replace the lambda probe or run into difficulties immediately after flushing (in the case of the Passat B32, the initial engine speed was approximately 1500). To study the instructions makes sense, and to control the actions of the mechanic.

The third. during the flushing process, try not to increase the engine speed by increasing the idle speed (especially for older cars with fairly cunning fuel systems). Just turning the idle screwdriver, you will doom the engine to heavy duty, because the throttle will be closed (or covered) and air access, respectively, is limited. The result is a rich mixture, but for a lambda probe and catalyst this is not very useful.

The main problems with the Passat B32 arose most likely precisely for this reason. Until the remnants of the cleaner carrier on candles, in the combustion chamber and dirt on the lambda probe and catalyst burned out, the engine worked in an unstable mode.

You can simply tighten the corresponding screw on the throttle actuator, put a temporary wedge or, in extreme cases, hold the desired speed for about fifteen minutes by pressing on the gas (in the latter case, the cleaner will also work in the additional injection system).

And the last one. Do not expect your car to turn into a beast immediately after flushing the fuel system. For this you need to drive 30-50 kilometers.