We independently repair mono-injection on Volkswagen Passat B3

Single injection device for Volkswagen Passat

Mono-injection system on Volkswagen Passat B3

Single injection is a type of fuel supply system into the combustion chambers of an engine. It differs from all the others in that it has only one nozzle and only through it do all cylinders receive the fuel mixture . Mono injection has both pros and cons. On the one hand, an engine with mono-injection starts more easily, since the operation of the system is monitored by a special valve, and mono-injection is designed simpler than a classic injector. On the other hand, repairing a single injection is more expensive, and its operation is highly dependent on the quality of the power supply.

Setting up mono injection in garage conditions

Adjustment or adjustment of the injection device on (VW) Volkswagen can be done independently in a garage. This does not require any experience or special skills. The main thing is to strictly follow the algorithm of actions indicated below and focus on all the advice of professionals.

Required Tools

Before repairing the Passat B3 mono-injection unit, you must first prepare the necessary tools and additional accessories. Among them, in the process of work you may need the following:

• screwdriver;
• open-end wrenches;
• new spark plugs of the appropriate type;
• socket heads with collar;
• multimeter for taking measurements;
• sandpaper for cleaning contacts;
• electrical tape for working with wires;
• flat tongs;
• gasket for single injection (if it is damaged);
• distributor cover (if there are cracks).

It is worth paying attention to the fact that not all additional devices indicated in the list may be needed. This directly depends on what exactly caused the malfunction.

Step by step guide

The repair process must occur in several stages:

1. It is necessary to check the resistance of the air temperature sensor that enters the system. To do this you need to use a multimeter. The values ​​obtained with its help should be compared with the normal values ​​​​that are indicated in the manual for using the car. If the temperature range is from 20 to 25 degrees, then the resistance should be in the range of 1800-1900 Ohms. As the sensor heats up, you should see a decrease in resistance. By cooling it increases. This needs to be checked using a multimeter, independently raising and lowering the temperature.
2. The next stage of repair is checking the resistance on the mono injector nozzle. In the working position it can range from 1.2 to 1.6 Ohms. Due to the fact that the multimeter does not measure very accurately, small errors in these indicators are still allowed.
3. Next you need to adjust the idle speed. To do this, it is necessary to send a voltage of 12 V from the battery to the contacts of the regulator. At the same time, the accelerator should be set to its extreme position. Then we check for the presence of a short circuit (SC). To do this, the probe must be placed in the gap formed between the accelerator end and the rod itself. It is worth understanding if the gap is too significant. the multimeter will not be able to show the presence of a short circuit. In such a situation, adjustment or adjustment of the injection device on (VW) Volkswagen Pasat B three is required. To do this, you need to use a special screw located at the bottom of the assembly. With its help you can control the position of the limit switch.
4. Once the driver has successfully adjusted the mono-injection, he needs to clean it and carry out other work of the same kind. Only after this can you begin to adjust the position of the throttle valve of the unit. In order to do this, you need to connect a monoinjector. The injector connector should be connected to it. Then you need to connect the position and temperature sensor connector. Next, you need to move on to installing the fuel lines in their correct position. The driver should disconnect the terminals from the battery. Once this is done, the key must be turned in the ignition. This way you can reset all previous settings. In the end, all that remains is to connect the battery.

Signs and causes of malfunction

There is most often one symptom of uneven mono-injection: the engine speed suddenly begins to “float”, and it reacts poorly to pressing the gas pedal . This can happen either immediately after starting the engine or during the trip. The repair of the mono-injection system itself does not take much time. Much more time is spent identifying the cause of the breakdown. This task in the Volkswagen Passat B3 is seriously complicated by the fact that this car does not have a computer connection module, and therefore it is impossible to quickly carry out a full diagnosis.

We list the most common causes of uneven injection:

• The gasket installed directly under the mono-injection has lost its tightness.
• The contacts of the wires located under the mono-injection sensor have come loose.
• The problem occurred after the spark plugs were replaced with new ones.
• The seal of the distributor cover is broken (and the crack may not be visible to the naked eye, but it will be enough to cause malfunctions in fuel distribution).
• The compression created by the fuel pump is too high (or vice versa - too low).
• The throttle valve is clogged or covered with a thick layer of carbon deposits.
• The integrity of the wires going to the sensor that monitors the throttle position is broken.

Tuning and repairing single injection on Volkswagen Passat B3

A common problem for a common German car: how to set up and repair mono-injection on a Volkswagen Passat B3. This model is very common among the entire Volkswagen model range.

It is characterized by the following positive qualities: reliability, spaciousness, durability, ease of maintenance. In general, this car contains many characteristics that make it a truly people's car. It can also be noted that the interior is large and spacious, the car starts at very low temperatures, the body is made of high quality, the car is very playful for its age.

Thanks to these advantages , many people use the Passat B3 as a workhorse; it can be found everywhere: in the city, in the country, in the middle of a field, in the forest, in swamps, and while fishing. Although the car is very reliable, breakdowns and stability in engine operation are also common. So, one of the problems may be a floating engine speed, which is why the car begins to behave poorly, as people say - the car “stumbles”.

Even if the car starts up well, after a while while driving the speed may drop and the gas pedal seems to sink. These problems are associated with the mono-injection engine.

Setting up and repairing single injection on a Volkswagen Passat B3 is not a difficult task; the most important thing is to discover the cause of this problem. The complexity of computer diagnostics in this model is complicated by the lack of a computer connection module.

The problem with uneven mono-injection, as a rule, can be as follows:

• there is a gasket under the single injection, if the seal is broken, uneven distribution of fuel begins (replace the gasket);
• The device itself has a yellow sensor, under which the wires are hidden. You need to remove the sensor and check the integrity of the wire connection;
• the malfunction may be related to them (selection of the optimal type of spark plugs);
• The trampler cover may be broken (in this case it needs to be replaced). The hole may be small, not even visible to the naked eye;
• on the sensor that regulates the throttle position, the resistance should change without significant dips in the values ​​(checking the integrity of the wiring);
• improper compression of the fuel pump (repair or replacement of the fuel element);
• clogged fuel filter (replace with a new one);
• carbon deposits and clogged throttle valve (just disassemble and clean it).

The above are the main problems that play an important role in the operation of a single injection. If these troubleshooting options do not help, you should consult with specialists. After the mono-injection has been repaired, it is also necessary to adjust it correctly.

Setting up the single injection on the Volkswagen Passat B3 is carried out in the following order:

• you need to measure the resistance on the intake air temperature sensor with a multimeter and compare it with the table value (if work is carried out at room temperature 20-25°C, then the resistance value is at the level of 1.8-1.9 kOhm);
• when the intake air sensor heats up, the resistance drops; when cooled, it grows. If everything is exactly like this, then the sensor is working;
• we measure the resistance of the nozzle itself (resistance values ​​range from 1.2 to 1.6 Ohms). If you get values ​​above, check the error of the multimeter, it can be significant. This is described in more detail in the article “How to check injectors”;
• then we set the single injection idle clearance. By supplying 12 V voltage from the battery to the contacts of the regulator, we set the accelerator to its extreme position. We set the multimeter to “short circuit” mode and connect the contacts to the accelerator regulator. The following situation should arise: there should be a gap between the rod and the accelerator limit switch, insert the probe into this gap (ideally 0.45-0.5 mm), if the multimeter does not register a short circuit, then the distance is too large. It should be noted that during this procedure the adjusting bolt must be set according to the instructions. So, if the gap is too large, then we adjust the position of the accelerator limit switch with a screw located at the bottom of the mono-injection;
• adjust the throttle position. To do this, you need to install the mono-injection on the engine and connect the connector to the injector, throttle position sensor and intake air sensor. We connect the fuel hoses and remove the terminal from the battery, and turn the ignition key. This resets all on-board device settings. After that, connect the battery in place.

We measure the voltage on the first and fifth contacts of the throttle connector (with the ignition on), it should be 5-6 V. Then between contacts 1 and 2 the value is 0.186 V, if not, then we carry out the adjustment. To do this, loosen the 4 screws of the damper cover, connect the multimeter to contacts 1 and 2 and turn the cover in one or the other direction, changing the voltage.

At this point, the setup is complete, we assemble the mono-injection to the end and start the car. Thus, the single injection system on the Volkswagen Passat B3 is configured and repaired. If they are not afraid to get their hands dirty, and they grow from the right place, then there is nothing difficult about it. Doing everything yourself is much more pleasant than paying someone else a lot of money for it.

How the system works

Mono injection, in addition to the nozzle, consists of a temperature sensor, regulator and fuel return line. Compared with modern parameters, single injection requires very little pressure.

1. The nozzle through which fuel is directed into the chamber is opened by a special controller.
2. The fuel dosage is controlled by a valve, and the air supply is controlled by a throttle valve (DZ), controlled by an electric drive. The finished fuel assembly ends up in the cylinder that opened earlier than the others.
3. Pressure stabilization is carried out by a regulator of the same name. It does not allow air pockets to enter the system when the internal combustion engine is turned off. Thanks to this design solution, starting the engine is easier.