It often happens that the car engine runs intermittently, despite the fact that the on-board computer does not give errors. The fuel supply pressure is normal, the sensors are intact, and the idle speed jumps from 550 to 1100. If a similar problem occurred on the Prior, then the cause may be hiding in a throttle valve malfunction.
What is this node for
Throttle valve "Priora" is an element of the fuel system for internal combustion engines with fuel injection. It acts as a valve that supplies air from the air filter to the intake manifold. When the damper is in the open position, the air is supplied to the full, and the pressure in the manifold and in the atmosphere becomes the same. If it is closed, then a vacuum is created.
On the Priore, the throttle valve is controlled in two ways - electrically and mechanically.
The first models came with a cable drive. When you press the gas pedal, the force was transmitted mechanically.
The “Priors” throttle body additionally combines a position sensor for this element of the intake system and an idle speed controller that sets the crankshaft speed when the damper is closed, as well as at the moment the engine is started and when additional electrical equipment is connected: headlights, air conditioner, interior heater electric motor. It works from the electric drive. Which supplies air through the valve, bypassing the damper.
In addition, the housing is part of the cooling and crankcase ventilation system. The Priory throttle valve with 16 valves differs from the auto damper with 8 valves by an additional hole on the perimeter of the housing from the intake manifold side.
Since 2011, VAZ cars have been equipped with an electronic gas pedal, which led to a change in the design of the Priora throttle valve.
Now the mechanism is driven by an electric motor connected through a gearbox. The idle speed regulator has been eliminated as unnecessary. The drive is controlled through the on-board computer, which, based on the readings of the damper position sensor, regulates the fuel mixture in the best possible way. The amount of opening began to depend not only on the accelerator, but also on the clutch and brake pedal. The shutter comes to its original position with the help of a return mechanism consisting of a spring.
Electronic drive keeps speed constantengine when driving with various loads, even without the participation of the driver.
Opening the hood of the Priora, you won't be able to see the throttle assembly. It is located under a plastic casing that covers the top of the engine. In addition to the aesthetic load, it carries the function of protecting against a heated valve cover.
After removing the casing, the air supply system will appear. It is a large rubber pipe connected on one side to the air filter box, and on the other to the intake manifold. Between them, the Priory throttle valve assembly is installed. It looks like an dural insert with a plastic black lamb in the form of a sector, to which a control cable is connected (in the case of a mechanical drive).
Practice shows that the throttle needs to be cleaned at intervals of 40-60 thousand kilometers. The time when such a need arises can be determined by the following signs:
- Unstable rpm.
- Long return to idle when releasing the accelerator pedal.
- Difficulty starting the engine after a long period of inactivity. Even in warm weather.
- There is a smell of gasoline in the exhaust gases, indicating that the mixture is too rich.
Manufacturer recommends cleaning every 50 thousand km. The owners of the Priora car on thematic forums give different numbers. Some do not resort to this procedure throughout the use of the machine.Much depends on the operating conditions: the region, the timeliness of replacing the air filter.
How to clean the throttle assembly yourself
Cleaning the damper is one of the procedures that is easy to do on your own. Time takes no more than an hour.
Work is done on a cold engine. Before you start, you need to prepare wrenches, Phillips and flathead screwdrivers and carburetor cleaner. To clean the throttle valve "Lada Priory", you need to do the following:
- Put the car on the parking brake.
- Disconnect the negative battery terminal.
- Remove the plastic protective cover from the engine. To do this, unscrew the oil filler cap. Remove 4 rubber plugs around the perimeter of the casing. Then unfasten the adsorber valve with a screwdriver and remove the wires to the side. After removing the cover, the oil filler cap must be reinstalled to prevent dirt from entering the engine.
- Disconnect Priors throttle sensor and idle speed control connectors.
- Disconnect the cooling system hoses that heat the damper when the engine is running. Before loosening the clamps, you need to partially drain the coolant. Not completely, but only below the level of the throttle assembly. To do this, open the cap of the expansion tank and, substituting a flat container under the radiator, unscrew the cap of the radiator.
- Disconnect crankcase ventilation pipes.
- Loosen the clamp and remove the airnozzle.
- Unscrew the two bolts securing the throttle assembly to the intake manifold.
- Disconnect the gas pedal cable. To do this, use a screwdriver to unhook the bracket that secures the metal tip of the cable.
The resulting hole must be immediately closed with a rag. Otherwise, everything that gets inside will immediately be sucked into the engine at the time of starting.
Before cleaning the part, you must additionally remove the sensors from the housing. This should only be done for the power-driven assembly. As for the damper with electronic gas, a control unit is fixed on its body, which does not need to be removed. Moreover, when flushing with a carburetor cleaner, care must be taken to ensure that the cleaner does not get on the control box.
While cleaning the internal cavity, it is not recommended to change the position of the Priora throttle valve with electronic gas, as the drive gears can be damaged. The mechanical damper, on the contrary, can be rotated by the drive, fully opening access to the inside. It is also possible to detach the damper from the axis of rotation. It is secured with two bolts. However, you need to know how hard to twist back. If self-loosening occurs after assembly, the bolts will fall into the combustion chambers of the engine. To prevent this from happening, after finishing work, you need to drive 500 km, disassemble the assembly again and tighten the damper fasteners.
After assembly, do not forget to add coolant to the working level.