Engines 4A-F, 4A-FE, 5A-FE, 7A-FE and 4A-GE (AE92, AW11, AT170 and AT160) 4-cylinder, in-line, with four valves per cylinder (two intake, two exhaust ), with two overhead camshafts. 4A-GE engines are distinguished by the installation of five valves per cylinder (three inlet, two outlet).
Engines 4A-F, 5A-F are carbureted. all other engines have electronically controlled multipoint fuel injection.
The 4A-FE engines were made in three versions, which differed from each other mainly in the design of the intake and exhaust systems.
The 5A-FE engine is similar to the 4A-FE engine, but differs from it in the size of the cylinder-piston group. The 7A-FE engine has slight design differences from the 4A-FE. The engines will have cylinder numbering starting from the side opposite to the power take-off. The crankshaft is full support with 5 main bearings.
The bearing shells are made on the basis of an aluminum alloy and are installed in the bores of the engine crankcase and main bearing caps. The drills in the crankshaft are used to supply oil to the connecting rod bearings, connecting rod rods, pistons and other parts.
The order of the cylinders: 1-3-4-2.
The cylinder head, cast from an aluminum alloy, has transverse and opposite inlet and outlet pipes arranged with hipped combustion chambers.
The spark plugs are located in the center of the combustion chambers. The 4A-f engine uses a traditional intake manifold design with 4 separate intake manifolds that are combined into a single channel under the carburetor mounting flange. The intake manifold is liquid-heated, which improves the throttle response of the engine, especially when it is warmed up. The intake manifold of 4A-FE, 5A-FE engines has 4 independent pipes of the same length, which, on the one hand, are united by a common intake air chamber (resonator), and on the other, they are joined to the intake channels of the cylinder head.
The intake manifold of the 4A-GE engine has 8 of these, each fitting a different intake valve. The combination of the length of the intake pipes with the valve timing of the engine allows the phenomenon of inertial boost to be used to increase torque at low and medium engine speeds. The outlet and inlet valves mate with springs that have an uneven pitch.
The camshaft of the exhaust valves of engines 4A-F, 4A-FE, 5A-FE, 7A-FE is driven from the crankshaft using a flat-toothed belt, and camshaft intake valves are driven from camshaft exhaust valves using gear transmission. In the 4A-GE engine, both shafts are driven by a flat toothed belt.
The camshafts have 5 bearings located between the valve tappets of each cylinder; one of these supports is located at the front end of the cylinder head. Lubrication of the bearings and cams of the camshafts, as well as the drive gears (for engines 4A-F, 4A-FE, 5A-FE), is carried out by the oil flow entering through the oil channel drilled in the center of the camshaft. The valve clearance is adjusted using shims located between the cams and the valve tappets (for 20-valve 4A-GE engines, the adjusting spacers are located between the tappet and the valve stem).
The cylinder block is cast from cast iron. it has 4 cylinders. The upper part of the cylinder block is covered by the cylinder head, and the lower part of the block forms the crankcase in which the crankshaft... The pistons are made of high temperature aluminum alloy. Recesses are made on the piston bottoms to prevent the piston from meeting the valves in the TMV.
The piston pins of the 4A-FE, 5A-FE, 4A-F, 5A-F and 7A-FE engines are of the “fixed” type: they are fitted with an interference fit in the piston head of the connecting rod, but have a sliding fit in the piston bosses. Piston pins of the 4A-GE engine - "floating" type; they have a sliding fit both in the piston head of the connecting rod and in the piston bosses. Such piston pins are secured against axial displacement by retaining rings installed in the piston bosses.
The upper compression ring is made of stainless steel (4A-F, 5A-F, 4A-FE, 5A-FE and 7A-FE engines) or steel (4A-GE engine), and the 2nd compression ring is cast iron. The oil scraper ring is made of an alloy of common steel and stainless steel. The outer diameter of each ring is slightly larger than the piston diameter, and the elasticity of the rings allows them to tightly wrap around the cylinder walls when the rings are installed in the piston grooves. Compression rings prevent gases from escaping from the cylinder into the crankcase, and an oil scraper ring removes excess oil from the cylinder walls, preventing it from entering the combustion chamber.
Maximum non-flatness:
-
4A-fe, 5A-fe, 4A-ge, 7A-fe, 4E-fe, 5E-fe, 2E .... 0.05 mm
-
2C …………………………………………… 0.20 mm
"A"(R4, strap)
Engines of the A series, in terms of prevalence and reliability, share, perhaps, the primacy with the S series. As for the mechanical part, it is generally difficult to find more competently designed motors. At the same time, they have good maintainability and do not create problems with spare parts.
Installed on cars of classes "C" and "D" (families Corolla / Sprinter, Corona / Carina / Caldina).
4A-FE
- the most common engine in the series, without significant changes
produced since 1988, has no pronounced design defects
5A-FE
- a variant with a reduced displacement, which is still produced at Toyota's Chinese factories for internal needs
7A-FE
- more recent modification with increased volume
In the optimal production version, the 4A-FE and 7A-FE went to the Corolla family. However, when installed on Corona / Carina / Caldina vehicles, they eventually received a LeanBurn-type power system designed for combustion of lean mixtures and helping to save japanese fuel during quiet driving and in traffic jams (more about design features- cm. in this material on which models the LB was installed - It should be noted that here the Japanese have pretty much "spoiled" our ordinary consumer - many owners of these engines are faced with
the so-called "LB problem", which manifests itself in the form of characteristic dips at medium speed, the cause of which cannot be properly established and cured - either the low quality of local gasoline is to blame, or problems in the power supply and ignition systems (to the state of the candles and high-voltage wires, these engines especially sensitive), or all together - but sometimes the lean mixture simply does not ignite.
Small additional disadvantages - a tendency to increased wear of the camshaft beds and formal difficulties with adjusting the clearances during intake valves although in general it is convenient to work with these motors.
"The 7A-FE LeanBurn engine is slow, and even more powerful than the 3S-FE due to the maximum torque at 2800 rpm."
The LeanBurn version of the 7A-FE is one of the most common misconceptions about the outstanding low-speed torque of the 7A-FE. All civil engines of the A series have a "double humped" torque curve - with the first peak at 2500-3000 and the second at 4500-4800 rpm. The heights of these peaks are almost the same (the difference is almost 5 Nm), but the STD engines get a little higher than the second peak, while the LB has the first. Moreover, the absolute maximum torque for STD is still greater (157 versus 155). Now let's compare with the 3S-FE. The maximum moments of the 7A-FE LB and 3S-FE type "96 are 155/2800 and 186/4400 Nm, respectively. But if we take the characteristics as a whole, then the 3S-FE with the same 2800 comes out at the moment of 168-170 Nm, and 155 Nm - gives out already in the region of 1700-1900 rpm.
4A-GE 20V - a boosted monster for small GTs replaced in 1991 the previous base engine of the entire A series (4A-GE 16V). To provide 160 hp, the Japanese used a block head with 5 valves per cylinder, VVT system(for the first time using variable valve timing on Toyota), tachometer redline for 8 thousand. Minus - such an engine will inevitably be stronger "ushatan" in comparison with the average production 4A-FE of the same year, since it was originally bought in Japan not for economical and gentle driving. The requirements for gasoline (high compression ratio) and for oils (VVT drive) are more serious, so it is intended primarily for those who know and understand its features.
With the exception of 4A-GE, the engines are successfully powered by gasoline with octane number 92 (including LB, for which the RF requirements are even milder). Ignition system - with distributor ("distributor") for serial versions and DIS-2 for later LB (Direct Ignition System, one ignition coil for each pair of cylinders).
| Engine | 5A-FE | 4A-FE | 4A-FE LB | 7A-FE | 7A-FE LB | 4A-GE 20V |
| V (cm 3) | 1498 | 1587 | 1587 | 1762 | 1762 | 1587 |
| N (hp / at rpm) | 102/5600 | 110/6000 | 105/5600 | 118/5400 | 110/5800 | 165/7800 |
| M (Nm / at rpm) | 143/4400 | 145/4800 | 139/4400 | 157/4400 | 150/2800 | 162/5600 |
| Compression ratio | 9,8 | 9,5 | 9,5 | 9,5 | 9,5 | 11,0 |
| Gasoline (recommended) | 92 | 92 | 92 | 92 | 92 | 95 |
| Ignition system | tramble. | tramble. | DIS-2 | tramble. | DIS-2 | tramble. |
| Valve bend | No | No | No | No | No | Yes** |
Reliable japanese engines
04.04.2008
The most common and by far the most widely repaired Japanese engine is the Toyota 4, 5, 7 A - FE engine. Even a novice mechanic, diagnostician knows about possible problems engines of this series.
I will try to highlight (put together) the problems of these engines. There are few of them, but they cause a lot of trouble to their owners.
Date from scanner:
On the scanner, you can see a short but capacious date, consisting of 16 parameters, by which you can realistically evaluate the operation of the main engine sensors.
Sensors:
Oxygen sensor - Lambda probe
Many owners turn to diagnostics due to increased fuel consumption. One of the reasons is a banal break in the heater in the oxygen sensor. The error is recorded by the code control unit number 21.
The heater can be checked with a conventional tester on the sensor contacts (R- 14 Ohm)
Fuel consumption increases due to the lack of correction during warming up. You will not be able to restore the heater - only replacement will help. The cost of a new sensor is high, but it does not make sense to install a used one (the resource of their operating time is large, so this is a lottery). In such a situation, the less reliable NTK universal sensors can be installed as an alternative.
Their service life is short, and the quality is poor, so such a replacement is a temporary measure, and it should be done with caution.
With a decrease in the sensitivity of the sensor, an increase in fuel consumption occurs (by 1-3 liters). The performance of the sensor is checked with an oscilloscope on the block diagnostic connector, or directly on the sensor chip (number of switchings).
temperature sensor
If the sensor does not work properly, the owner will face a lot of problems. If the measuring element of the sensor breaks down, the control unit replaces the sensor readings and fixes its value at 80 degrees and fixes error 22. The engine, in case of such a malfunction, will work in normal mode, but only while the engine is warm. Once the engine has cooled down, it will be problematic to start it without doping, due to the short opening time of the injectors.
It is not uncommon for the resistance of the sensor to change chaotically when the engine is running on H.H. - the revolutions will float.
This defect can be easily fixed on the scanner by observing the temperature reading. On a warm engine, it should be stable and not change randomly from 20 to 100 degrees.
With such a defect in the sensor, "black exhaust" is possible, unstable operation on the Х.Х. and as a consequence, increased consumption, as well as the impossibility of starting "hot". Only after 10 minutes of rest. If there is no complete confidence in the correct operation of the sensor, its readings can be substituted by including a 1 kΩ variable resistor in its circuit, or a constant 300 ohm one, for further verification. By changing the sensor readings, it is easy to control the change in speed at different temperatures.
Position sensor throttle
A lot of cars go through the disassembly assembly procedure. These are the so-called "constructors". When removing the engine in the field and subsequent assembly, the sensors suffer, on which the engine is often leaned against. If the TPS sensor breaks, the engine stops throttling normally. The engine chokes when accelerating. The machine switches incorrectly. The control unit fixes error 41. When replacing a new sensor, it must be adjusted so that the control unit correctly sees the X.X sign when the gas pedal is fully released (throttle valve closed). In the absence of a sign of idling, adequate regulation of the Х.Х will not be carried out. and there will be no forced idling during engine braking, which again will entail increased fuel consumption. On engines 4A, 7A, the sensor does not require adjustment, it is installed without the possibility of rotation.
THROTTLE POSITION …… 0%
IDLE SIGNAL ……………… .ON
Sensor absolute pressure MAP
This sensor is the most reliable of all installed on Japanese cars. Its reliability is simply amazing. But it also has a lot of problems, mainly due to improper assembly.
Either the receiving "nipple" is broken, and then any passage of air is sealed with glue, or the tightness of the supply tube is violated.
With such a rupture, fuel consumption increases, the level of CO in the exhaust rises sharply up to 3%. It is very easy to observe the operation of the sensor using a scanner. The line INTAKE MANIFOLD shows the vacuum in the intake manifold, which is measured by the MAP sensor. If the wiring is broken, the ECU registers error 31. At the same time, the opening time of the injectors sharply increases to 3.5-5 ms. During gas re-gasings, a black exhaust appears, the candles are planted, a shaking appears on the X.X. and stopping the engine.
Knock sensor
The sensor is installed to register detonation knocks (explosions) and indirectly serves as a "corrector" for the ignition timing. The recording element of the sensor is a piezoplate. In the event of a sensor malfunction, or a break in the wiring, at overgazings of more than 3.5-4 tons. The ECU registers an error 52. There is lethargy during acceleration.
You can check the operability with an oscilloscope, or by measuring the resistance between the sensor terminal and the case (if there is resistance, the sensor needs to be replaced).
Crankshaft sensor
A crankshaft sensor is installed on the 7A series engines. A conventional inductive sensor, similar to the ABC sensor, is practically trouble-free in operation. But embarrassment also happens. With an interturn short circuit inside the winding, the generation of pulses is disrupted at certain speeds. This manifests itself as a limitation of engine speed in the range of 3.5-4 t. Rpm. A kind of cutoff, only at low revs. It is quite difficult to detect an interturn short circuit. The oscilloscope does not show a decrease in the amplitude of pulses or a change in frequency (with acceleration), and it is rather difficult to notice changes in Ohm fractions with a tester. If symptoms of speed limitation occur at 3-4 thousand, just replace the sensor with a known good one. In addition, a lot of trouble is caused by damage to the driving ring, which is damaged by careless mechanics when they replace the front crankshaft oil seal or timing belt. Having broken the teeth of the crown, and restoring them by welding, they achieve only a visible absence of damage.
At the same time, the crankshaft position sensor ceases to adequately read information, the ignition timing begins to change chaotically, which leads to a loss of power, unstable work engine and increased fuel consumption
Injectors (nozzles)
During many years of operation, the nozzles and needles of the injectors are covered with resins and gasoline dust. All this naturally interferes with the correct spray pattern and reduces the performance of the nozzle. In case of severe contamination, a noticeable shaking of the engine is observed, and fuel consumption increases. It is realistic to determine the clogging by conducting a gas analysis, according to the oxygen readings in the exhaust, it is possible to judge the correctness of the filling. A reading greater than one percent will indicate the need to flush the injectors (if correct installation Timing and normal fuel pressure).
Or by installing the injectors on the bench and checking the performance in tests. The nozzles are easy to clean with Laurel, Vince, both in CIP installations and in ultrasound.
The valve is responsible for the engine speed in all modes (warm-up, idle, load). During operation, the valve petal becomes dirty and the stem wedges. The revolutions freeze on heating or on HH (due to a wedge). Tests for changing the speed in scanners when diagnosing by this motor not provided. You can evaluate the valve's performance by changing the readings of the temperature sensor. Put the engine in "cold" mode. Or, removing the winding from the valve, twist the valve magnet with your hands. Sticking and wedge will be felt immediately. If it is impossible to easily dismantle the valve winding (for example, on the GE series), you can check its operability by connecting to one of the control outputs and measuring the duty cycle of the pulses while simultaneously controlling the H.X. speed. and changing the load on the engine. On a fully warmed-up engine, the duty cycle is approximately 40%, changing the load (including electrical consumers) can estimate an adequate increase in speed in response to a change in duty cycle. With mechanical jamming of the valve, there is a smooth increase in the duty cycle, which does not entail a change in the speed of H.H.
You can restore work by cleaning carbon deposits and dirt with a carburetor cleaner with the winding removed.
Further adjustment of the valve is to set the H.H. speed. On a fully warmed-up engine, by rotating the winding on the mounting bolts, tabular revolutions are achieved for this type of car (according to the tag on the hood). By pre-installing the jumper E1-TE1 in the diagnostic block. On the "younger" motors 4A, 7A, the valve was changed. Instead of the usual two windings, a microcircuit was installed in the body of the valve winding. Changed the valve power and the color of the winding plastic (black). It is already pointless to measure the resistance of the windings at the terminals on it.
The valve is supplied with power and a square-wave variable duty cycle control signal.
For the impossibility of removing the winding, non-standard fasteners were installed. But the problem of the wedge remained. Now if you clean it with an ordinary cleaner, the grease is washed out from the bearings (the further result is predictable, the same wedge, but due to the bearing). It is necessary to completely dismantle the valve from the throttle body and then carefully flush the stem with a petal.
Ignition system. Candles.
A very large percentage of cars come to the service with problems in the ignition system. When operating on low-quality gasoline, spark plugs are the first to suffer. They are covered with a red coating (ferrosis). There will be no high-quality sparking with such candles. The engine will run intermittently, with gaps, fuel consumption increases, the level of CO in the exhaust rises. Sandblasting cannot clean such candles. Only chemistry will help (silit for a couple of hours) or replacement. Another problem is the increase in clearance (simple wear).
Drying of the rubber tips of high-voltage wires, water that got in during the washing of the motor, which all provoke the formation of a conductive track on the rubber tips.
Because of them, the sparking will not be inside the cylinder, but outside it.
With smooth throttling, the engine runs stably, and with sharp throttling, it “crushes”.
In this position, it is necessary to replace both candles and wires at the same time. But sometimes (in the field), if replacement is impossible, you can solve the problem with an ordinary knife and a piece of emery stone (fine fraction). With a knife we cut off the conductive path in the wire, and with a stone we remove the strip from the ceramic of the candle.
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 incorrect procedure for replacing the plugs. The wires are forcibly pulled out of the wells, tearing off the metal tip of the rein.
With such a wire, misfires and floating revolutions are observed. When diagnosing the ignition system, always check the performance of the ignition coil on the high-voltage spark gap. The simplest check is to look at the spark on the spark gap while the engine is running.
If the spark disappears or becomes threadlike, this indicates an interturn short circuit in the coil or a problem in the high-voltage wires. Wire breakage is checked with a resistance tester. Small wire 2-3kom, further to increase the long 10-12kom.
The resistance of a closed coil can also be checked with a tester. The secondary resistance of the broken coil will be less than 12kΩ.
The next generation coils do not suffer from such ailments (4A.7A), their failure is minimal. Proper cooling and the thickness of the wire eliminated this problem.
Another problem is the leaking oil seal in the distributor. Oil on the sensors corrodes the insulation. And when exposed to high voltage, the slider is oxidized (covered with a green coating). The coal turns sour. All this leads to the disruption of sparking.
In motion, chaotic shots are observed (into the intake manifold, into the muffler) and crushing.
" Thin " malfunctions Toyota engine
On modern engines Toyota 4A, 7A the Japanese changed the firmware of the control unit (apparently for more quick warm-up engine). The change lies in the fact that the engine reaches H.H. rpm only at a temperature of 85 degrees. The design of the engine cooling system has also been changed. Now the small cooling circle passes intensively through the block head (not through the branch pipe behind the engine, as it was before). Of course, the cooling of the head has become more efficient, and the engine as a whole has become more efficient. But in winter, with such cooling when driving, the engine temperature reaches 75-80 degrees. And as a result, constant warming up revolutions (1100-1300), increased fuel consumption and nervousness of the owners. You can deal with this problem either by insulating the engine more strongly, or by changing the resistance of the temperature sensor (by deceiving the ECU).
Butter
Owners pour oil into the engine indiscriminately, without thinking about the consequences. Few people understand that Various types oils are incompatible and, when mixed, form an insoluble slurry (coke), which leads to the complete destruction of the engine.
All this plasticine cannot be washed off with chemistry, it can only be cleaned out mechanically. It should be understood that if you do not know what type of old oil, then you should use flushing before changing. And more advice to the owners. Pay attention to the color of the handle oil dipstick... It is yellow in color. If the color of the oil in your engine is darker than the color of the handle, it's time to make a change, and not wait for the virtual mileage recommended by the engine oil manufacturer.
Air filter
The most inexpensive and readily available element is the air filter. Owners very often forget about replacing it, without thinking about the likely increase in fuel consumption. Often, due to a clogged filter, the combustion chamber is very heavily contaminated with burned oil deposits, valves and candles are heavily contaminated.
When diagnosing, it can be mistakenly assumed that wear is to blame. valve stem seals, but the root cause is a clogged air filter, which increases the vacuum in the intake manifold when contaminated. Of course, in this case, the caps will also have to be changed.
Some owners do not even notice about living in the building air filter garage rodents. Which speaks of their utter disregard for the car.
Fuel filteralso deserves attention. If it is not replaced in time (15-20 thousand mileage), the pump starts to work with overload, the pressure drops, and as a result, it becomes necessary to replace the pump.
The plastic parts of the pump impeller and non-return valve wear out prematurely.
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). At reduced pressure, there are constant lumbago in the intake manifold, the start is problematic (after). Draft is noticeably reduced. Check pressure correctly with a pressure gauge. (access to the filter is not difficult). In the field, you can use the "return filling test". If, when the engine is running, less than one liter flows out of the gas return hose in 30 seconds, it is possible to judge the reduced pressure. You can use an ammeter to indirectly determine the pump's performance. If the current consumed by the pump is less than 4 amperes, then the pressure is sagged.
You can measure the current on the diagnostic block.
When using a modern tool, the process of replacing the filter takes no more than half an hour. Previously, it took a lot of time. Mechanics always hoped in case that they were lucky and the lower fitting did not rust. But it often did.
I had to puzzle for a long time with which gas wrench to hook the rolled nut of the lower fitting. And sometimes the process of replacing the filter turned into a "movie show" with the removal of the tube leading to the filter.
Today, no one is afraid to make this replacement.
Control block
Before 1998 release,
control units didn't have enough serious problems during operation.
The blocks had to be repaired only for a reason"
hard polarity reversal"
... It is important to note that all outputs of the control unit are signed. It is easy to find on the board the required sensor lead to check,
or wire rings. The parts are reliable and stable in operation at low temperatures.
In conclusion, I would like to dwell a little on gas distribution. Many owners "with hands" perform the belt replacement procedure on their own (although this is not correct, they cannot properly tighten the crankshaft pulley). Mechanics make a quality replacement within two hours (maximum). If the belt breaks, the valves do not meet the piston and fatal engine failure does not occur. Everything is calculated to the smallest detail.
We tried to tell you about the most common problems on Toyota A series engines. The engine is very simple and reliable and subject to very tough operation on water -iron gasoline"And the dusty roads of our great and mighty Motherland and the" awkward "mentality of the owners. Having endured all the bullying, he continues to delight his reliable and stable work, having won the status of the best Japanese engine.
All the early identification of problems and easy repair of the Toyota 4, 5, 7 A - FE engine!
Vladimir Bekrenev, Khabarovsk
Andrey Fedorov, Novosibirsk
© Legion-Avtodata
UNION OF AUTOMOTIVE DIAGNOSTICS
You will find information on car maintenance and repair in the book (s):
The 7A-FE engine was produced from 1990 to 2002. The first generation, built for Canada, had 115 hp. at 5600 rpm and 149 Nm at 2800 rpm. From 1995 to 1997 was produced special version for the USA, the power of which was 105 hp. at 5200 rpm and 159 Nm at 2800 rpm. Indonesian and Russian versions of the engine are the most powerful.
Specifications
| Production | Kamigo Plant Shimoyama plant Deeside Engine Plant North Plant Tianjin FAW Toyota Engine's Plant No. 1 |
| Engine brand | Toyota 7A |
| Years of release | 1990-2002 |
| Cylinder block material | cast iron |
| Supply system | injector |
| Type of | inline |
| Number of cylinders | 4 |
| Valves per cylinder | 4 |
| Piston stroke, mm | 85.5 |
| Cylinder diameter, mm | 81 |
| Compression ratio | 9.5 |
| Engine displacement, cubic cm | 1762 |
| Engine power, hp / rpm | 105/5200 110/5600 115/5600 120/6000 |
| Torque, Nm / rpm | 159/2800 156/2800 149/2800 157/4400 |
| Fuel | 92 |
| Environmental standards | - |
| Engine weight, kg | - |
| Fuel consumption, l / 100 km (for Corona T210) - town - track - mixed. |
7.2 4.2 5.3 |
| Oil consumption, gr. / 1000 km | up to 1000 |
| Engine oil | 5W-30 / 10W-30 / 15W-40 / 20W-50 |
| How much oil is in the engine | 4.7 |
| Oil change is carried out, km | 10000 (better than 5000) |
| Engine operating temperature, deg. | - |
| Engine resource, thousand km - according to the plant - on practice |
n.d. 300+ |
Common malfunctions and operation
- Increased burnout of gasoline. The lambda probe does not function. An urgent replacement is required. If there is a plaque on candles, dark exhaust and shaking on Idling, the absolute pressure sensor needs to be corrected.
- Vibration and excessive consumption of gasoline. It is necessary to clean the nozzles.
- Speed problems. Need diagnostics of the valve at idle, as well as clean the throttle valve and check the sensor of its location.
- There is no start of the motor when the speed is out of order. The unit heating sensor is to blame.
- Instability of the speed. It is necessary to clean the throttle valve block, KXX, candles, crankcase valves and nozzles.
- The engine stalls regularly. Defective fuel filter, distributor or fuel pump.
- Increased oil consumption over a liter per 1,000 km. It is necessary to change the rings and valve stem seals.
- Knocking on the motor. The reason is loose piston pins. It is necessary to adjust the valve clearances every 100 thousand kilometers.
On average, 7A is a good unit (in addition to the Lean Burn version) with a mileage of up to 300 thousand km.
7A engine video
The development of A-series engines at Toyota started back in the 70s of the last century. This was one of the steps to reduce fuel consumption, increase efficiency, so all units of the series were quite modest in terms of volumes and capacities.
The Japanese achieved good results in their work in 1993 by releasing another modification of the A series - the 7A-FE engine. At its core, this unit was a slightly modified prototype of the previous series, but it is rightfully considered one of the most successful internal combustion engines in the series.
Technical details
ATTENTION! Found a completely simple way to reduce fuel consumption! Don't believe me? An auto mechanic with 15 years of experience also did not believe until he tried it. And now he saves 35,000 rubles a year on gasoline!
The volume of the cylinders was increased to 1.8 liters. The motor began to issue 120 Horse power, which is a fairly high figure for such a volume. The characteristics of the 7A-FE engine are interesting in that the optimum torque is available from low revs. For city driving, this is a real gift. And it also allows you to save fuel without cranking the engine in lower gears to high revs... In general, the characteristics are as follows:
| Years of production | 1990–2002 |
| Working volume | 1762 cubic centimeters |
| Maximum power | 120 horsepower |
| Torque | 157 N * m at 4400 rpm |
| Cylinder diameter | 81.0 mm |
| Piston stroke | 85.5 mm |
| Cylinder block | cast iron |
| Cylinder head | aluminum |
| Gas distribution system | DOHC |
| Fuel type | petrol |
| Predecessor | 3T |
| Successor | 1ZZ |
7a-fe under the hood toyota caldina
Highly interesting fact is the existence of two types of 7A-FE engine. In addition to conventional powertrains, the Japanese have developed and actively promoted the more economical 7A-FE Lean Burn to the market. Maximum efficiency is achieved by leaning the mixture in the intake manifold. To implement the idea, it was necessary to use special electronics, which determined when it was necessary to lean the mixture, and when it was necessary to put more gasoline into the chamber. According to the owners of cars with such an engine, the unit has a lower fuel consumption.
Features of operation 7A-FE
One of the advantages of the motor design is that the destruction of such a unit as the 7A-FE timing belt eliminates the collision of the valves and the piston, i.e. in simple terms, the engine does not bend the valve. The engine is inherently very durable.
Some owners of advanced 7A-FE lean-burn units say that the electronics often behave in an unpredictable manner. It is not always when you press the accelerator pedal that the mixture depletion system is turned off, and the car behaves too calmly, or begins to twitch. Other problems with this power unit, are private and not massive.
Where was the 7A-FE engine installed?
Conventional 7A-FEs were intended for C-class vehicles. After a successful test start of the engine and good feedback from the drivers, the concern began to install the unit on the following vehicles:
| Model | Body | Of the year | Country |
|---|---|---|---|
| Avensis | AT211 | 1997–2000 | Europe |
| Caldina | AT191 | 1996–1997 | Japan |
| Caldina | AT211 | 1997–2001 | Japan |
| Carina | AT191 | 1994–1996 | Japan |
| Carina | AT211 | 1996–2001 | Japan |
| Carina e | AT191 | 1994–1997 | Europe |
| Celica | AT200 | 1993–1999 | Except for Japan |
| Corolla / Conquest | AE92 | September 1993 - 1998 | South Africa |
| Corolla | AE93 | 1990–1992 | Australia only |
| Corolla | AE102 / 103 | 1992–1998 | Except for Japan |
| Corolla / Prizm | AE102 | 1993–1997 | North America |
| Corolla | AE111 | 1997–2000 | South Africa |
| Corolla | AE112 / 115 | 1997–2002 | Except for Japan |
| Corolla spacio | AE115 | 1997–2001 | Japan |
| Corona | AT191 | 1994–1997 | Except for Japan |
| Corona premio | AT211 | 1996–2001 | Japan |
| Sprinter Carib | AE115 | 1995–2001 | Japan |
