Toyota Carina e floating idle speed

The Japanese car Toyota Carina E, despite its venerable age, still remains quite in demand and widespread among domestic motorists.

Like all other cars, the Carina E has an engine cooling system directly connected to the interior heating system. This unit may occasionally experience problems.

There are several main reasons why a working heater suddenly stops performing its functions, does not heat the interior at all, or does it much worse than before.

Idle system 3S-FE

The idle speed sensor (or valve, as it is also called) on an internal combustion engine is designed to regulate the speed of the car engine while idling. The adjustment occurs by changing the amount of air entering the cylinders through an additional channel (“bypass”, bypass channel), bypassing the closed throttle valve. The amount of incoming air is taken into account by the air flow mass sensor. In turn, this information is sent to the engine control unit, which controls the supply of the appropriate amount of fuel.

Thus, the engine maintains constant speed in idle mode. The channel capacity is determined by the location of the valve spool, which is driven by the coils (solenoids) of the XX regulator. The magnetic field they create allows you to deflect the spool to the angle required for normal operation of the motor.

In case of failure of the electromagnetic element of the system, a mechanical method is provided to open the channel. The main elements of this mechanism are a spring (bimetallic spiral) and a valve lever. The special properties of the spring allow it to respond to the temperature of the liquid in the cooling system, changing its stiffness. Thus, the position of the stop and the angle of installation of the spool change. In this situation, the engine idle speed will be increased. It turns out that the spring duplicates the functions of the 3S-FE engine idle speed sensor, so that in case of failure the car does not stall.

It is also worth considering that a change in spring stiffness is caused solely by a change in coolant temperature. Therefore, unlike a working XX sensor, it cannot respond to connections to the on-board consumer network. When checking the adjustment of this mechanism, you should pay attention to the speed (with the DXX connector disconnected, it should be 1000-1200 rpm).

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The engine is the “heart” of a car, and like the human heart, interruptions sometimes occur in the functioning of this “organ”. We become aware of problems with the engine by reading the rpm. If the speed of the power unit begins to float, the engine gives us a signal that something is wrong with it. In our material today we will tell you what breakdowns are hinted at by jumping engine speeds, how to correctly diagnose and repair them.

The reason for the appearance of floating speed

The driver can find out that there is something wrong with the engine speed by looking at the tachometer. During normal operation of the power unit at idle, the needle of this device remains at the same level (usually within 750-800 rpm), and if the engine has problems, the needle either falls or rises (range from 500 to 1,500 rpm and higher). If the car does not have a tachometer, then the floating speed can be heard by ear: the rumble of the engine either increases or decreases. And also - by the increasing and decreasing vibrations penetrating into the car interior from the engine compartment.

Dismantling

To remove the idle air valve on a 3S-FE, you first need to remove the air filter cover, after loosening the clamp and disconnecting the temperature sensor. Afterwards, remove the pipe leading to the throttle body, also loosening the clamp and pulling out the cable and hoses.

Remove the cable casing, loosen its fastening bolts, and then remove the coolant pipes (dismantle only when the engine is cool!) and the “vacuum” hose. Disconnect the chips from the idle speed sensor and the DS position sensor, then unscrew the bolts and nuts securing the DS. Finally, we remove the idle speed sensor winding, and then the valve itself (pay attention to the gasket, try not to damage it).

Cleaning the XX valve

To clean the 3S-FE idle valve, you will need a brush and an ordinary “carb cleaner” (carburetor cleaning fluid). The main contamination of the valve is carbon deposits (plaque) on its internal part. You can soak the valve in cleaning fluid for several hours.

After the procedure, rotation of the valve should be very easy and unimpeded. At the same time, it is worth cleaning the throttle mechanism: there is no need to disassemble it. After moistening with cleaning liquid, carefully clean the unit with a rag or toothbrush. Assembly is carried out in reverse order. Before screwing it into place, it is worth applying a thin layer of sealant to the electromagnet.

Settings

If the car's speed fluctuates at idle, or even more, the car simply stalls at idle, or the speed is too high, you should think about adjusting the idle speed sensor. Since his work is closely related to BDZ, it is necessary to start with him.

Remote sensing position

First you need to pay attention to the gap between the throttle drive stop and the stop screw. There should be no gap in the closed position of the damper. Please note that this screw does not regulate engine idle speed, but simply prevents wear on the damper.

Don't be surprised if you find the screw head sawed off. Many vehicles have this installed from the factory. A serviceable and adjusted damper moves smoothly, without jerking when starting, and does not require additional forces when pulled from its place.

Throttle position sensor

The throttle position sensor can be adjusted without removing it.

loosen the fastening bolts;
use a 0.7 probe to connect to contacts IDL – E2;
by gently tapping with a hammer, you need to catch the moment when the resistance on the multimeter is equal to infinity (that is, the conductivity disappears);
tighten the bolt of the upper sensor mounting, check everything according to the manual;
tighten the bottom bolt and carry out a control check with all probes on all contacts.

It is worth noting that the resistance at the IDL – E2 contacts in itself does not matter, the main thing is that it does not exceed the permissible limit according to the manual (2.3 kOhm).

Spring adjustment

On the 3S-FE engine, the idle air valve is designed in such a way that the “shutter” can be opened either by an electromagnetic solenoid or by a spring, without the use of electronics. As already noted, this was done so that in the event of a failure of the electric mechanism, the engine does not stall, but continues to operate at idle.

Electric fan

There may be several factors at once, one way or another related to the stove fan:

The blades broke. This rarely happens on the Toyota Carina E. But since these cars are quite old, natural wear and tear has not been canceled. You will have to replace the impeller or the entire fan.
The fuse has blown. In this case, the stove will not turn on at all. Look for the fuse in the appropriate block. Check whether there is an element with the required resistance value, as recommended by the manufacturer.
The resistor is broken. With its help, the stove on the Carina E has several speeds. If the resistor on the electric fan breaks, the heater does not operate at all speeds except the highest. Need a replacement.
The motor itself broke down. There may be a problem with the brushes or bearing, for example. It is hardly possible to carry out the repair yourself. Easier to replace completely.
Wiring and control unit. There may be mechanical failure of the regulators responsible for controlling the heater on the Toyota Carina E, or breakage, chafing of wires, or corrosion of contacts. They need to be checked, cleaned, tested with a multimeter, and, if necessary, the wires or the entire control unit must be replaced.

These are the most common and most likely problems that can affect the heater on a Toyota Carina E. Most faults can be fixed on your own.

But if difficulties arise, it is better to contact specialized specialists.

Revs fluctuate on Toyota Corolla: causes and their elimination

Long-term operation of automotive equipment without servicing its components, as a rule, leads to breakdowns or malfunctions in the operation of certain systems. Any car needs constant attention and care. In this article we will discuss the problem when the speed fluctuates on a Toyota Corolla, we will try to understand it and fix it.

Floating speed of a car in our country is a very common problem that has affected any car owner at least once. The problem can arise for various reasons, and now we will talk about it.

Air inside the system

Airing of the system, due to which the liquid does not circulate through the circuit, is caused by air entering there. Most often due to incorrect replacement, a faulty valve cover of the expansion tank, or due to damaged tubes.

It is much worse if air penetrates through a broken cylinder block gasket.

To solve this problem on the Toyota Carina E, you need to bleed the system, remove air from there, after first making sure there are no leaks.

Why can the idle speed fluctuate?

The effect of floating speed occurs most often in cars with electronic fuel injection and is associated with excessive air supply. Here the whole problem rests on the system control unit or the computer, which regulates the air supply to the overall system.

The computer must provide a sufficient amount of air entering the cylinders, while taking into account the readings of a number of sensors. After processing and reading information from the latter, the computer opens the injector solenoid valves at one time or another. When a failure occurs and excess air enters, the throttle sensor indicates that there has been an oversaturation of air and it should not be there, and the temperature sensor dictates its rules to the control unit and indicates that the engine has already left the warm-up and air-saturated mode Less fuel needs to be poured. As a result of a sensor conflict, the computer has a problem - it does not understand where to put the excess air. This whole situation, as a rule, leads to the fact that engine speeds begin to fluctuate from 800 rpm, then 1200 rpm, and so a periodicity of 3-5 seconds occurs. Floating speeds cause great inconvenience for the driver, increase fuel consumption and disrupt the operation of the fuel supply system. If such a problem occurs, it must be eliminated.

If such a situation arises, we will try to correct the situation ourselves. First, let's tighten the speed control screw - by doing so we will close the hole through which the air enters and we will be able to stabilize the air supply. By tightening the bolt, the excess rich mixture should be compensated. If this operation does not give the effect we need and does not restore the speed, we can try to squeeze the rubber tubes; if, by squeezing one of the tubes, the engine speed levels out and becomes quite stable, we need to remove it from the pipe and determine where the excess air is coming from. The most common causes of excess air are devices such as:

Starting device for Toyota Corolla;
Device for maintaining speed;
Any valve;
Or, as practice shows, the crankcase ventilation valve of a Toyota Corolla engine.

If, after all the tubes were clamped one by one, a solution to the problem was not found, you can safely remove the air duct in front of the throttle valve. Having removed it, in front of the throttle valve you can find a hole with a diameter of about 1 centimeter - through this hole air flows bypassing the throttle valve. It’s worth starting the engine and plugging the hole with your fingers; if this doesn’t help, then let’s move on to the next possible cause of floating speed.

It’s worth checking all the sensors - we check for contamination and external damage; for a more detailed inspection, you will need a specialist who can test the car’s sensors; if the specialist finds nothing, we check the throttle cable. It should be reasonably tensioned, but should not initially open the throttle assembly. If everything is in order with the cable, the tubes have no damage or obvious cracks, there is only one reason for this behavior of the car - a clogged throttle valve.

Coolant

To begin with, it is worth noting that some situations are extremely simple, but car owners think about them at the very last moment, having carried out a complex of complex repair and restoration work.

Having noticed that the heater is not working well in the cabin of the Toyota Carina E, there is a musty smell and high humidity, it makes sense to check the condition of the cabin filter. If it is clogged and worn out, similar symptoms will appear. The filter is located to the right of the pedal assembly. Getting to him is not so easy, but it is possible.

One of the primary tasks is checking the current level of antifreeze in the expansion tank.

The stove may not work if the system is deficient in antifreeze. It could simply evaporate or leak out. Leakage may occur through hoses or a damaged tank. It’s worse if antifreeze penetrates into other systems due to a leak in the circuit.

First, try just adding antifreeze. In 80% of cases this solves the problem.

Step-by-step cleaning of the throttle body on a Toyota Corolla

So, let's start cleaning the throttle. First, it’s worth talking about exactly what tools we need. For removal and cleaning we need:

Special product for cleaning carburetors;
A few clean and dry rags, preferably lint-free;
A set of keys, various sockets and screwdrivers - which will help in removing the throttle;
You also need a room in which the relevant work can be carried out.

Having decided on the tools and materials, we proceed to removing the throttle. Disconnect the pipe, throttle cable and two sensors. The photo below shows where the throttle is located.

Next, we need to unscrew the bolts securing the damper - unscrew several nuts and bolts, and then carefully remove the damper from its place. This is not difficult to do, but you should be careful and careful not to damage the unit. So, the knot is removed. The photo below shows what a dirty throttle valve looks like. It is because of this dirt that instability of engine operation and floating speed on the tachometer can occur.

We removed the throttle. We take the aerosol we bought for cleaning carburetors and thoroughly spray the entire throttle body, both inside and out. It is important to remember that it is best to use chemical-resistant gloves, as the aerosol is very caustic. We spray and wait 20-30 minutes until the applied liquid corrodes the dirt and it can not be easily washed off.

After waiting a little time, we wash the throttle with gasoline, then wipe it clean and let it dry. It is advisable to carry out cleaning in a place without drafts and wind, so that dust does not get stuck in the various cracks of the damper. The photo below shows what a clean damper looks like. This is exactly the result we should strive for.

After all cleaning, we put the damper back on, not forgetting to put on the sensors, throttle cable and air duct. We start the car and check its performance. Most likely, the speed will return to its previous position, the car will work quietly and calmly, as if you had just bought it.

This concludes cleaning the damper, searching for the problem and eliminating it. When the cause of the breakdown has been eliminated, it is worth talking about how to prevent such phenomena from occurring:

The first and most important thing is to change the air filters in a timely manner and not let the car become covered in dust;
The second and also no less important is that you, as a driver, should look for normal, clean fuel for your car - you should not refuel your car at dubious gas stations;
And finally, thirdly, the car needs timely maintenance - the throttle valve should be cleaned at least once every 10-15 thousand kilometers. This point is mandatory, because at one point the car will simply let you down.

We'll stop there. The three points presented are mandatory, since next time the car simply will not start. Timely inspection and cleaning of your car will help significantly save your money and minimize your digging under the hood to find problems.

Source: corollafan.ru