"Reliable Japanese engines." Notes of the automotive diagnostic. Reliable Japanese Toyota engines Series A Engine 7A FE Technical Disadvantages

Engines 5A, 4A, 7A-Fe
The most common and today is the most widely repaired from Japanese engines is the engines of the series (4,5,7) A- Fe. Even a novice mechanic, the diagnostics know about possible problems engines in this series. I will try to highlight (assemble in a single integer) the problems of these engines. They are a bit, but they deliver a lot of trouble to their owners.

Date from the scanner:

On the scanner you can see a short, but a capacitive date consisting of 16 parameters for which you can really appreciate the operation of the main engine sensors.

Sensors
Oxygen sensor -

Many owners are drawn to the diagnosis due to increased fuel consumption. One of the reasons is a banal intro heater in the oxygen sensor. The error is fixed by the code control unit number 21. Checking the heater can be carried out by a conventional tester on the sensor contacts (R-14 Ohm)

Fuel consumption increases due to lack of correction when warming up. You will not be able to restore the heater - only replacement will help. The cost of the new sensor is large, and the b \\ y does not make sense (the resource of their developments is great, so this is a lottery). In such a situation, as an alternative, less reliable universal NTK sensors can be installed. The term of their work is small, and the quality leaves much to be desired, therefore such a replacement of the temporary measure, and it should be made with caution.

With a decrease in the sensitivity of the sensor, an increase in fuel consumption (by 1-3l). The performance of the sensor is checked by an oscilloscope on the block diagnostic connectoror directly on the sensor's chip (switching number).

Temperature sensor.
If the owner's sensor is incorrect operation, there is a lot of problems. When the sensor measuring element is cut, the control unit replaces the sensor readings and fixes its value of 80 degrees and fixes the error 22. The engine, with such a malfunction, will work in normal mode, but only until the engine is heated. As soon as the engine cools, run it is problematic without doping, due to the small opening of the injectors. There are cases when the resistance of the sensor is chaotically changed when the engine is running on H.H. - Turns will swim

This defect is easy to fix on the scanner, watching the temperature indication. On the heated engine, it must be stable and not change chaotic values \u200b\u200bfrom 20 to 100 degrees

With this sensor defect, "black exhaust" is possible, unstable work on H.H. and as a consequence, increased flow, as well as the impossibility of running "to hot". Only after 10 minutes of sludge. If not full confidence In the proper operation of the sensor, its testimony can be replaced by turning on its chain with a variable resistor 1k, or permanent 300, for further verification. By changing the sensor readings, the change in revolutions is easily controlled at different temperatures.

Position sensor throttle valve

Many cars undergoing a disassembly assembly procedure. These are the so-called "designers". When removing the engine in the field and the subsequent assembly, sensors suffer to which the engine often lean. When the TPS sensor faults, the engine stops normally throttling. The engine when the rotation set is chopped up. The machine switches incorrectly. An error 41 is fixed by the control unit. When replacing a new sensor, you must configure that the control unit correctly seen a sign of H.H., with a fully released gas pedal (closed throttle). In the absence of a sign of idling, adequate regulation of H.H. will not be carried out. And there will be no mode of forced idling when braking the engine, which will again entail an increased fuel consumption. On the 4A engines, the 7a sensor does not require adjustment, it is installed without the possibility of rotation.
Throttle Position ...... 0%
Idle Signal .................. .on

Absolute Pressure Sensor MAP

This sensor is the most reliable, from all installed on japanese cars. The reliability is simply striking. But and his share has a lot of problems, mainly due to improper assembly. He is either broken down by the "nipple", and then seal with glue any passage of air, or the tightness of the supply tube is disturbed.

With this break, the fuel consumption increases, the level of CO in exhaust up to 3% increases. Very easy to observe the operation of the sensor on the scanner. The INTAKE Manifold line shows the discharge in the intake manifold, which is measured by the Mar sensor. When the entry wiring, the ECU registers the error 31. At the same time, the opening time of the injectors up to 3.5-5ms is sharply incremented And engine stop.

Knock sensor

The sensor is set to register detonation stuffs (explosions) and indirectly serves as a "corrector" of the ignition advance angle. The registering element of the sensor is Punoplastin. If the sensor malfunction, or the wiring break, on the passages over 3.5-4 tons. ECU turns fixes the error 52. It becomes intimidating when acceleration. You can check the performance by an oscilloscope, or, measuring, resistance between the sensor output and the housing (if there is resistance, the sensor requires replacement).

Crankshaft sensor
On the 7a series engines set the crankshaft sensor. An ordinary inductive sensor is similar to the ABC sensor, and practically sureless in operation. But confusions happen. With interstitious closure inside the winding, a disruption of the generation of pulses on certain revolutions occurs. This is manifested as a limit of engine speed in the range of 3.5-4 tons. Revolutions. A kind of cut-off, only on low revolutions. Detect the intersensile closure is quite difficult. The oscilloscope does not show a decrease in the amplitude of the pulses or the frequency change (during acceleration), and the tester notice the changes in the shares of Ohm is quite difficult. If the symptoms occur the revolutions limit on 3-4 thousand, simply replace the sensor on knowingly serviceable. In addition, a lot of trouble gives damage to the masterful crown, which damage the negligent mechanics, producing work on the replacement of the front oscillation of the crankshaft or the timing belt. To break the trunk of the crown, and restoring them with welding, it seems only the visible absence of damage. The crankshaft position sensor ceases to adequately read the information, the ignition advance angle begins to change chaotically, which leads to loss of power, unstable work Engine and increase fuel consumption

Injectors (nozzles)

With many years of operation, the nozzles and needles of the injectors are coated with resins and gasoline dust. All this naturally disrupts the correct spray and reduces the performance of the nozzle. With severe contamination, there is a tangible engine shaking, fuel consumption increases. Determine the accuracy really, by conducting gas analyzes, according to the testimony of oxygen in the exhaust, one can judge the correctness of the pouring. The testimony over one percent will indicate the need for washing injectors (when proper installation Timing and normal fuel pressure). Either by installing the injectors to the stand, and checking the performance in tests. The nozzles are easy to wash the laurel, Vince, both on installations for non-bleaching, and in ultrasound.

Idling valve, IACV

The valve is responsible for engine speed in all modes (heating, idling, load). During operation of the valve petal, the stem is contaminated and occurs. Turns hang on warming up either on H.H. (due to the wedge). Tests for changing revolutions in scanners during the diagnosis of this motor is not provided. You can estimate the performance of the valve by changing the temperature sensor readings. Enter the engine to "Cold" mode. Or, removing the winding from the valve, to twist over the valve magnet. Singing and wedge will be tangible immediately. If it is impossible to dismantle the valve winding (for example, on the GE series), it is possible to check its performance by connecting to one of the control outputs and measuring the diversity of the pulses at the same time controlling the turns of H.Kh. and changing the load on the engine. On a fully heated engine, the unit is approximately 40%, changing the load (including electrical consumers), you can estimate an adequate increase in revolutions in response to a change in duty. With a mechanical valve jamming, a smooth extension of the duty is occurring, not entailing the change in the revolutions of H.H. You can restore the work. Cleaning the Nagar and the dirt of the carburetor cleaner when the winding is removed.

Further adjustment of the valve is to install H.Kh. On a fully heated engine, rotating winding on the mounting bolts, achieve table revs for this type car (on the tag on the hood). After setting the E1-TE1 jumper into the diagnostic shoe. On more "young" engines 4a, 7a valve has been changed. Instead of the familiar two windings in the body of the valve winding, installed a chip. Changed the nutrition of the valve and the color of the winding plastic (black). It is noiencies to measure the resistance of windings on the conclusions. The valve is supplied and the control signal of the rectangular shape of the variable duty.

For the impossibility of removing the winding, a non-standard fastener was installed. But the problem of the wedge remained. Now, if you clean the usual cleaner, the lubricant is washed out of the bearings (the further result is predictable, the same wedge, but already due to the bearing). It is necessary to completely dismantle the valve from the throttle block and then wash the rod with petal carefully.

Ignition system. Candles.

A very large percentage of cars comes to service with problems in the ignition system. When operating on low-quality gasoline, the ignition candles suffer primarily. They are covered with a red raid (ferry). There will be no qualitative sparking with such candles. The engine will work with interruptions, with skipping, increases fuel consumption, the level of CO in the exhaust increases. Sandblasts are unable to clean such candles. Only chemistry will help (a couple of hours) or replacement. Another problem increases the gap (simple wear). Drying rubber tips of high-voltage wires, water that fell when washing the motor, which all this provoke the formation of a conductive path on rubber tips.

Because of them, sparking will not be inside the cylinder, and outside it.
When smooth throttling, the engine works stably, and with a sharp - "crusher".

With this position it is necessary to replace both the candles and wires. But sometimes (in field conditions) If the replacement is impossible, you can solve the problem with a conventional knife and a piece of sandy stone (shallow fraction). I cut a knife with a conductive path in the wire, and with a stone remove the strip from the candle ceramics. It should be noted that it is impossible to remove the rubber band from the wire, this will lead to the complete inoperability of the cylinder.

Another problem is related to the wrong procedure for replacing candles. Wires with power are pulling out of the wells, pulling the metal tip of the occasion.

With such a wire, ignition skips and floating turns are observed. When diagnosing the ignition system, you should always check the ignition coil on the high-voltage discharge. The simplest check - on the engine running engine, see the spark on the discharge.

If the spark disappears or becomes a filamental - this indicates an intersless closure in the coil or on the problem in high voltage wires. Cutting the wires check the test tester. Small wire 2-3k, further to an increase long 10-12.

The resistance of the closed coil can also be checked by the tester. The resistance of the secondary winding of the coil bit will be less than 12.
Next generation coils are not suffering such a few (4a.7a), their refusal is minimal. Proper cooling and wire thickness excluded this problem.
Another problem is the current seal in the distributor. Oil, falling on the sensors, corrosive insulation. And when exposed to high voltage, the slider is oxidized (covered with a green bloom). Corner zaks. All this leads to the breakdown of spar formation. In motion there are chaotic strips (in the intake manifold, in the muffler) and crushing.

« Thin "malfunctions
On the modern engines 4A, 7A Japanese changed the firmware of the control unit (apparently for faster engine warming). The change lies in the fact that the engine reaches the turns of H.X.This at a temperature of 85 degrees. Also changed the design of the engine cooling system. Now the small circle of cooling intensively passes through the block of the block (not through the nozzle behind the engine, as before). Of course, the cooling of the head became more effective, the engine in general became more efficient. But in winter, with this cooling, when moving, the temperature of the engine reaches a temperature of 75-80 degrees. And as a result, permanent warming turns (1100-1300), increased fuel consumption and nerve owners. You can fight this problem, or the engine is stronger than the engine, or by changing the resistance of the temperature sensor (deceiving the ECU).
Butter
The owners pour oil into the engine without a special parsing without thinking about the consequences. Few people understand that various types of oils are not compatible and for mixing form an insoluble porridge (coke), which leads to the complete destruction of the engine.

All of this plasticine cannot be washed into chemistry, it is cleaned only by mechanical way. It should be understood if the old oil is unknown, it should be used before changing. And another advice to the owners. Pay attention to the color of the handle oil affection. It is yellow. If the color of the oil in your engine is darker color handles - it's time to replace, and not wait for the virtual mileage recommended by the manufacturer of the engine oil.

Air filter
The most inexpensive and easily accessible element - air filter. Owners very often forget about his replacement, without thinking about the likely increase in fuel consumption. Often, due to the scored filter, the combustion chamber is very polluted by oil burnt sediments, valve, candles are strongly polluted. Diagnosis can be mistakenly assumed that all wines siloslets Kolpacchkov, But the root cause is a scored air filter, which increases with dirt discharge in the intake manifold. Of course, in this case, the caps will also have to change.

Fuel filteralso deserves attention. If it does not replace it in time (15-20 thousand run) the pump begins to work with overload, pressure drops, and as a result, the need to replace the pump. Plastic impeller pump parts and check valve are prematurely wearing.

Pressure drops. It should be noted that the operation of the motor is possible at a pressure of up to 1.5 kg (with a standard 2.4-2.7 kg). Upon reduced pressure, there are permanent strips in the intake manifold Running problem (in terms of). The thrust is noticeably reduced. The pressure test is properly produced. (Access to the filter is not difficult). In the field, you can use the "pouring test from the return". If during the operation of the engine in 30 seconds from the gasoline, the gasoline is less than one liter flows, one can judge reduced pressure. It is possible for indirect determination of the pump performance to use an ammeter. If the current consumed by the pump is less than 4amper, then the pressure is seized. You can measure the current on the diagnostic shoe

When using the modern tool, the filter replacement process takes no more than half an hour. Previously, it took a lot of time. Mechanics always hoped in case they were lucky and the lower nozzle did not fit. But often it happened. I had to break my head with a long way to hook a rolling nut of the lower fitting. And sometimes the filter replacement process turned into a "film" with the removal of the tube applying to the filter.

Today, no one is afraid of this replacement.

Control block
Until 1998. year of releaseThe control blocks did not have enough serious problems when operating.

Repair blocks accounted for only because of the "hard ignition". It is important to note that all conclusions of the control unit are signed. It is easy to find the required output of the sensor to check, or the wire transversions. Details are reliable and stable at low temperatures.
In conclusion, I would like to stop a little on gas distribution. Many owners "with hands" procedure for replacing the belt are performed independently (although it is not correct, they cannot properly tighten the crankshaft pulley). Mechanics produce qualitative replacement Within two hours (maximum), when the belt belt is cut, the valves are not found with the piston and the fatal destruction of the engine does not occur. Everything is designed to smallest things.

We tried to tell about the most frequently arising problems on the engines of this series. The engine is very simple and reliable and subject to very tight operation on "water-iron gasolines" and dusty roads to our Great and Mighty Motherland and the "Avosny" mentality of the owners. All mockery, he still continues to delight his reliable and stable workBy won the status of the best Japanese engine.

All successful repairs.

"Reliable japanese engines" Notes car diagnostic

Japanese autoconecern Toyota began developing a power plant from the A-Series line in 1970. As a result, the engine 7a Fe was released. They differ in the presence of small amounts of fuel and weak power characteristics. The main objectives of the development of this engine:

• reduction of fuel mixture;
• increased efficiency.

The best engine of this series was created by the Japanese in 1993. He received a labeling 7a-Fe. This power unit combines the best qualities of previous units from this series.

Characteristics

The working volume of combustion chambers increased, compared with previous versions, and amounted to 1.8 liters. Achieving the power indicator equal to 120 horse poweris a good indicator for the power plant of this volume. Achieving the optimal torque is possible from the bottom speed of rotation crankshaft. Therefore, riding in the urban trait gives the enjoyment of the car owner. Despite this, fuel consumption remains low. Also, you do not need to scroll the engine on the lower gears.

Summary chart of characteristics

There are two types of 7a-Fe engines. Additional modification is marked as 7A-FE Lean Burn, and is a more economical version of the usual power aggregate. The intake manifold performs a function of combining and subsequent mixing of the mixture. It helps to increase the cost-effectiveness. Also in this engineinstalled a large number electronic systemsthat provide depletion or enrichment of the fuel and air mixture. Car owners, with this power plant, often leave feedback, which refers to a record low indicators of gasoline consumption.

Minuses of Motor

Power setting Toyota. 7Y is another modification, which was created by the example of the base motor 4a. However, it was replaced by a short-cooled crankshaft onto the knee, the course of which is 85.5 mm. As a result, there is an increase in the height of the cylinder block. With the exception of this, the design remained the same as in 4a-Fe.

The seventh engine from the A series is 7a-Fe. Changes in settings of this motor, allow you to determine the power parameter that could be from 105 to 120 hp. It also exists its additional modification with a reduced fuel consumption. However, the car with this power plant should not be purchased, as it is a capricious and quite expensive in service. In general, the design and problems are the same as in 4a. The rubber and sensors fail, a knock appears in piston system, due to incorrect settings. The release of it ended in 1998, when it was changed by 7a-Fe.

Features of operation

The main design advantage of the motor is that in the destruction of the surface of the belt of the gas distribution mechanism 7a-Fe, the possibility of colliding valves and pistons is eliminated. Simply put, the bending of the engine valves is impossible. In general, the engine is reliable.

Some car owners, with an improved power unit under the hood, complain about the unpredictability of electronic systems. For harsh pressed Gas pedals, the car does not always begin to gain overclocking dynamics. This happens because the system of depletion of the fuel and air mixture is not turned off. The nature of the remaining problems arising from the data power plantsare private and not received mass distribution.

What kind of car was this engine?

The installation of the base motor 7A-Fe was carried out on C-class cars. Test tests were successful, as well as the owners left a lot good reviewsso Japanese autoconecern began installing this power unit on the following models Toyota:

Chip tuning

The atmospheric version of the engine does not give the owner the possibility of a large increase in dynamic qualities. You can replace all design elements that can be changed and not achieve any result. The only node that will somehow increase the dynamics of overclocking is a turbine.

We bring to your attention the price for a contract engine (without run in the Russian Federation) 7A FE

The 7A-FE engine was made from 1990 to 2002. The first generation, built for Canada, had engine power 115 hp With 5,600 revolutions per minute and 149 nm at 2800 revolutions per minute. From 1995 to 1997 produced special version For the United States, the capacity of which was 105 hp At 5,200 revolutions per minute and 159 nm at 2800 revolutions per minute. Indonesian and Russian versions of the engine are the most powerful.

Specifications

Common malfunctions and operation

1. Increased gasoline facing. Lambd probe does not function. Required urgent replacement. If there is a flaw on the candlelight, dark exhaust and shaking on idlingYou need to fix the absolute pressure sensor.
2. Vibration and overrun gasoline. It is necessary to clean the nozzles.
3. Turns with revolutions. I need to diagnose the valve at idle, as well as clean the throttle valve and check the location sensor.
4. There is no start of the motor in the interruption of revolutions. To blame the heating sensor of the unit.
5. Unstability of the number of revolutions. It is necessary to clean the blade throttle block, khx, candles, crankcase valves and nozzles.
6. Regularly stalls the engine. Focused fuel filter, rubber or gas station.
7. Increased consumption of oil over liters per 1 thousand km. It is necessary to change rings and oil-challenged caps.
8. Tapping in the motor. The reason is the discharged piston fingers. It is necessary to adjust the valve clearances every 100 thousand km of way.

On average, 7a is a good unit (in addition to the version of LEAN BURN) when running up to 300 thousand km.

Video on the engine 7a