How to clean the Hyundai throttle body G4FA, G4FC

Owners of Korean cars are divided into two camps – one fanatically cleans the throttle almost every month, the other forgets where the throttle unit is 70-80 thousand km. Which of them is right and why clean the throttle body Hyundai Solaris and KIA Rio, now we will understand.

Hyundai Solaris and KIA Rio G4FA, G4FC throttle body. Working principle

Any modern injector engine is very meticulous about the quantity and quality of air entering the intake manifold and fuel. Hyundai Solaris and KIA Rio engines (G4FC, G4FA) have an electronic throttle control system.

Simply put, in the early injection engines, the valve was controlled by a mechanical drive, a conventional cable. The driver interacted directly with the throttle, and according to the degree of opening the damper, the electronic engine control unit calculated the required amount of fuel supplied to the combustion chamber through the injectors.

Hyundai Solaris and KIA Rio have introduced so-called electronic accelerator pedals in the new injection engines. It is a simple resistor sensor that sends a pulse to the ECU. The signal from the control unit is already fed to the gear motor of the throttle valve, which directly controls it.

It turns out that the driver does not have direct mechanical contact with the throttle, and interacts with it in the form of an electronic engine control unit.

At the same time, the ECU receives unlimited engine control options. Depending on the opening angle of the throttle valve, the electronics regulate the angle of ignition advance, the moment of fuel injection, and its quantity. The control unit is now based on the operating conditions of the engine, rather than on the driver’s commands.

The system takes into account primarily environmental standards, and then takes into account the load on the engine, crankshaft speed, antifreeze temperature and based on all these data regulates the ratio of air and fuel for the most efficient combustion of the mixture.

The main task of the throttle valve is to dose the air supply both at idle speed and under load.

With idle speed in motors with electronic throttle, there are also changes. If the valves with mechanical drive maintained the idle speed thanks to the idle regulator and the bypass channels of the throttle, the system with an electronic damper does not have all this good. Idle speed is regulated by the angle of the damper.

Why clean the throttle assembly on Hyundai and KIA

Therefore, even the lightest and inconspicuous soot and soot on the diffuser or on the damper itself can change the amount of air entering the intake.

At the same time, the electronics believe that the damper is open enough to provide 800 rpm. However, this does not happen when the damper becomes clogged and the ECU increases the fuel supply to reach nominal speed.

As a result, we have a whole bunch of troubles:

1. Unstable idling speed. They jump from 750 to 900 rpm, the engine runs intermittently.
2. Overconsumption of fuel both in the mode of single turns and under loading, at high speeds, at accelerations and start.
3. Poor engine start. The ECU can not immediately react to a clearly smaller amount of incoming air, the engine does not start, floods the spark plugs.
4. Jerks when accelerating and moving.
5. Uneven formation of the air-fuel mixture.

All these difficulties arise only due to changes in the cross-section of the diffuser when the valve is closed and open, the curvature of the compensation gap between the valve and the diffuser due to dirt, oil deposits, dust and soot.

That is why experienced drivers recommend cleaning the throttle assembly at least once every 30-40 thousand km, and if necessary more often.

How to properly clean the throttle body G4FA, G4FC

Old mechanically controlled chokes could be cleaned quickly without removing the housings from the engine. It was enough to spray directly into the diffuser of any carburetor cleaner from an aerosol can, start the engine, and then spray with the engine running. As an express cleansing, this method had the right to life.

With a new throttle equipped with electronic control, such tricks do not work.

1. First, one-way cleaning of the throttle assembly is inefficient, as a lot of soot and dirt accumulates from the intake manifold.
2. Secondly, the cleaner can easily get on the axis of the valve on the control board of the gear motor and damage both it and the throttle position sensors.

The tracks on the board are very thin and they are afraid of aggressive substances. It is almost hopeless to restore the damper control unit, so later you will have to buy a new one, which costs a little less than the entire throttle assembly.

The only way out is to remove the throttle assembly from the engine and only after that, taking care, clean it and wipe it to a shine with a clean cloth. It is good that the work here is a maximum of half an hour.

You will need a standard set of tools, a clean, lint-free cloth, and an aerosol cleaner to remove the choke. Praise the Abro aerosol, but any other will do.

Disassembly and cleaning of the throttle assembly on Hyundai and KIA is performed according to the following algorithm.

1. Be sure to remove the terminal from the battery, as we will work with contact pads, there is a risk of closing the wiring and disabling the ECU.
   
2. Remove the air filter assembly with housing and intake manifold. For this purpose, it is necessary to unscrew three bolts with a 10 mm socket.
3. We dissolve the clamps of the branch pipes tied to the corrugation of the air duct.
   
4. Remove the filter housing together with the air duct corrugation. If necessary, change the air filter.
   
5. Totally clean the surface of the housing from dust and dirt, if possible, blow with compressed air.
6. Disconnect the wiring harness block from the throttle motor reducer.
7. Carefully and quickly remove the inlet and outlet pipes of antifreeze from the fittings of the throttle body. Raise them quickly to lose a minimum of antifreeze. On average, it will take about 70-80 ml of fluid.
   
8. Unscrew the four bolts securing the throttle to the intake manifold by 10 mm socket. They are the same length, confuse when assembling will not work.
9. Carefully remove the throttle from the intake manifold, do not lose the rubber seal.

   

   

10. Now with the help of an aerosol and a clean cloth clean the valve itself, the diffuser, wipe the collector, as deep as you can get. With an aerosol – without fanaticism. Remember the control board and the track position sensors.

    

    

    

    

11. Wipe dry the throttle assembly, the landing plane of the collector and collect everything in reverse order.

    

    

    

    

Start the engine, if the idle speed is not stabilized, teach the throttle. To do this, shut down the engine and turn on the ignition for 3-6 minutes. The damper will automatically find the zero, closed position, agree with the ECU.

Then idle speed is stabilized and the iron will be kept within the nominal 800 rpm. Failures and twitches will disappear, fuel consumption will be reduced, Hyundai and KIA engines will behave completely differently.