Octane number
General advice and recommendations of the manufacturer - "What kind of gasoline do we pour into Toyota?"

Engine oil
General tips for choosing engine oil - "What kind of oil do we pour into the engine?"

Spark plug
General notes and a catalog of recommended candles - "Spark plug"

Batteries
Some recommendations and a catalog of standard batteries - "Batteries for Toyota"

Power
A little more about the characteristics - "Rated performance characteristics of Toyota engines"

Refueling tanks
Manufacturer's recommendation guide - "Filling volumes and liquids"

The most archaic OHV engines for the most part remained in the 1970s, but some of their representatives were modified and remained in service until the mid-2000s (K series). The lower camshaft was driven by a short chain or gears and moved the rods through hydraulic pushers. Today OHV is used by Toyota only in the truck diesel segment.

Since the second half of the 1960s, SOHC and DOHC engines of different series began to appear - initially with solid double-row chains, with hydraulic lifters or adjusting valve clearances with washers between the camshaft and the pusher (less often - screws).

The first series with a timing belt drive (A) was not born until the late 1970s, but by the mid-1980s, such engines - what we call "classics", had become absolute mainstream. First SOHC, then DOHC with the letter G in the index - "wide Twincam" with both camshaft drive from the belt, and then the massive DOHC with the letter F, where one of the shafts, connected by a gear transmission, was driven by a belt. The DOHC clearances were adjusted with washers above the push rod, but some Yamaha-designed motors retained the washers under the push rod.

In the event of a belt break, valves and pistons were not found on most mass engines, with the exception of the forced 4A-GE, 3S-GE, some V6s, D-4 engines and, of course, diesels. In the latter, due to the design features, the consequences are especially severe - the valves bend, the guide bushings break, the camshaft often breaks. For gasoline engines, a certain role is played by chance - in a “non-bending” engine, the piston and valve covered with a thick layer of carbon sometimes collide, and in a “bending” engine, on the contrary, the valves can successfully hang in the neutral position.

In the second half of the 1990s, fundamentally new third-wave engines appeared, on which the timing chain drive returned and the presence of mono-VVT (variable intake phases) became standard. Typically, chains drove both camshafts on in-line engines, on V-shaped ones between the camshafts of one head there was a gear drive or a short additional chain. Unlike the old double-row chains, the new long single-row roller chains were no longer durable. The valve clearances were now almost always set by the selection of adjusting pushers of different heights, which made the procedure too laborious, time-consuming, costly, and therefore unpopular - the owners for the most part simply stopped keeping track of the clearances.

For engines with a chain drive, cases of breakage are traditionally not considered, however, in practice, when overshooting or incorrect installation of the chain, in the overwhelming majority of cases, valves and pistons meet each other.

A kind of derivation among the motors of this generation turned out to be the forced 2ZZ-GE with a variable valve lift (VVTL-i), but in this form the concept of distribution and development was not developed.

Already in the mid-2000s, the era of the next generation of engines began. In terms of timing, their main distinguishing features are Dual-VVT (variable intake and exhaust phases) and revived hydraulic lifters in the valve drive. Another experiment was the second option for changing the valve lift - Valvematic on the ZR series.

The practical advantages of a chain drive compared to a belt drive are simple: strength and durability - the chain, relatively speaking, does not break and requires less frequent planned replacements. The second gain, layout, is important only for the manufacturer: the drive of four valves per cylinder through two shafts (also with a phase change mechanism), the drive of the injection pump, pump, oil pump - require a sufficiently large belt width. Whereas the installation of a thin single-row chain instead of it allows you to save a couple of centimeters from the longitudinal dimension of the engine, and at the same time to reduce the transverse dimension and the distance between the camshafts, due to the traditionally smaller diameter of the sprockets compared to pulleys in belt drives. Another small plus - less radial load on the shafts due to less pre-tension.

But we must not forget about the standard disadvantages of chains.
- Due to the inevitable wear and the appearance of play in the joints of the links, the chain stretches during operation.
- To combat chain stretching, either a regular "tightening" procedure is required (as on some archaic motors), or the installation of an automatic tensioner (which is what most modern manufacturers do). A traditional hydraulic tensioner operates from the general lubrication system of the engine, which negatively affects its durability (therefore, Toyota places it outside on chain engines of new generations, making replacement as easy as possible). But sometimes the chain stretching exceeds the limit of the tensioner adjustment capabilities, and then the consequences for the engine are very sad. And some third-rate car manufacturers manage to install hydraulic tensioners without a ratchet mechanism, which allows even an unworn chain to "play" with every start.
- During operation, a metal chain inevitably "saws through" the shoes of tensioners and dampers, gradually wears out the sprockets of the shafts, and wear products get into the engine oil. Even worse, many owners do not change sprockets and tensioners when replacing a chain, although they should understand how quickly an old sprocket can ruin a new chain.
- Even a serviceable timing chain drive always works noticeably louder than a belt drive. Among other things, the speed of the chain is uneven (especially with a small number of sprocket teeth), and there is always an impact when the link engages.
- The cost of the chain is always higher than the timing belt kit (and is simply inadequate for some manufacturers).
- Changing the chain is more laborious (the old "Mercedes" method does not work on Toyota cars). And in the process, a fair amount of accuracy is required, since the valves in Toyota chain motors meet pistons.
- Some engines originating from Daihatsu do not use roller chains, but gear chains. By definition, they are quieter in operation, more accurate and more durable, however, for inexplicable reasons, they can sometimes slip on the asterisks.

As a result - have the maintenance costs decreased with the transition to timing chains? A chain drive requires one or another intervention no less often than a belt drive - hydraulic tensioners are rented out, on average, the chain itself stretches for 150 tkm ... and the costs "per circle" turn out to be higher, especially if you do not cut out the details and replace all the necessary components at the same time drive.

The chain can be good - if it is two-row, the engine has 6-8 cylinders, and there is a three-pointed star on the cover. But on classic Toyota engines, the timing belt drive was so good that the transition to thin long chains was a clear step backward.

In the post-Soviet space, the carburetor power supply system for locally produced cars will never have competitors in terms of maintainability and budget. All deep electronics - EPHH, all vacuum - UOZ machine and crankcase ventilation, all kinematics - throttle, manual suction and drive of the second chamber (Solex). Everything is relatively simple and straightforward. The penny cost allows you to literally carry a second set of power and ignition systems in the trunk, although spare parts and "equipment" could always be found somewhere nearby.

The Toyota carburetor is a completely different matter. It is enough to look at some 13T-U from the turn of the 70s-80s - a real monster with many tentacles of vacuum hoses ... Well, the late "electronic" carburetors generally represented the height of complexity - a catalyst, an oxygen sensor, an exhaust air bypass, a bypass exhaust gases (EGR), suction control electrics, two or three stages of idle speed control by load (power consumers and power steering), 5-6 pneumatic drives and two-stage dampers, tank and float chamber ventilation, 3-4 electro-pneumatic valves, thermo-pneumatic valves, EPHH, vacuum corrector , an air heating system, a full set of sensors (coolant temperature, intake air, speed, detonation, DZ limit switch), a catalyst, an electronic control unit ... It's surprising why such difficulties were needed at all in the presence of modifications with normal injection, but this or otherwise, such systems, tied to vacuum, electronics and drive kinematics, worked in a very delicate balance. It was elementary to break the balance - not a single carburetor is insured against old age and dirt. Sometimes everything was even more stupid and simpler - the excessively impulsive "master" disconnected all the hoses in a row, but, of course, did not remember where they were connected. Somehow it is possible to revive this miracle, but it is extremely difficult to establish the correct operation (so that a normal cold start, normal warm-up, normal idling, normal load correction, normal fuel consumption are maintained at the same time) is extremely difficult. As you might guess, a few carburetors with knowledge of Japanese specifics lived only within Primorye, but two decades later, even local residents are unlikely to remember them.

As a result, Toyota's distributed injection initially turned out to be simpler than later Japanese carburetors - there were not much more electrics and electronics in it, but the vacuum degenerated greatly and there were no mechanical drives with complex kinematics - which gave us such valuable reliability and maintainability.

The most unreasonable argument in favor of the D-4 is that "direct injection will soon replace conventional motors." Even if this was true, it would in no way indicate that there is no alternative to engines with HB. now... For a long time, D-4 meant, as a rule, one specific engine in general - the 3S-FSE, which was installed on relatively affordable mass-produced cars. But they were equipped with only three 1996-2001 Toyota models (for the domestic market), and in each case, the direct alternative was at least the version with the classic 3S-FE. And then the choice between D-4 and normal injection usually remained. And since the second half of the 2000s, Toyota generally abandoned the use of direct injection on engines of the mass segment (see. "Toyota D4 - prospects?" ) and began to return to this idea only ten years later.

"The engine is excellent, it's just that our gasoline (nature, people ...) is bad" - this is again from the field of scholasticism. This engine may be good for the Japanese, but what is the use of this in Russia? - a country of not the best gasoline, a harsh climate and imperfect people. And where, instead of the mythical advantages of D-4, only its disadvantages come out.

It is extremely unfair to appeal to foreign experience - "but in Japan, but in Europe" ... The Japanese are deeply concerned about the contrived CO2 problem, the Europeans combine blinkeredness on reducing emissions and efficiency (it is not for nothing that diesel engines occupy more than half of the market there). For the most part, the population of the Russian Federation cannot compare with them in income, and the quality of local fuel is inferior even to states where direct injection was not considered until a certain time - mainly because of unsuitable fuel (besides, the manufacturer of a frankly bad engine can be punished there with a dollar) ...

The stories that "the D-4 engine consumes three liters less" is just plain misinformation. Even according to the passport, the maximum economy of the new 3S-FSE in comparison with the new 3S-FE on one model was 1.7 l / 100 km - and this is in the Japanese test cycle with very quiet modes (therefore, the real savings were always less). In dynamic city driving, the D-4 operating in power mode does not reduce consumption in principle. The same happens when driving fast on the highway - the zone of tangible efficiency of the D-4 in terms of revs and speeds is small. And in general, it is incorrect to argue about the "regulated" consumption for a by no means new car - it depends much more on the technical condition of a particular car and driving style. Practice has shown that some of the 3S-FSE, on the contrary, spend significantly more than the 3S-FE.

You could often hear "yes, you will change the pump quickly and there is no problem." Say what you don’t say, but the obligation to regularly replace the main unit of the engine fuel system with a relatively fresh Japanese car (especially Toyota) is just nonsense. And even with a regularity of 30-50 t.km, even a "penny" $ 300 was not the most pleasant waste (and this price concerned only 3S-FSE). And little was said about the fact that the injectors, which also often required replacement, cost money comparable to the injection pump. Of course, the standard and, moreover, already fatal problems of 3S-FSE in the mechanical part were diligently hushed up.

Perhaps not everyone thought about the fact that if the engine has already "caught the second level in the oil pan", then most likely all rubbing parts of the engine have suffered from working on a petrol-oil emulsion (do not compare the grams of gasoline that sometimes get into the oil when cold starting and evaporating as the engine warms up, with liters of fuel constantly flowing into the crankcase).

Nobody warned that on this engine it is impossible to try to "clean the throttle" - that's all correct adjustments to the engine control system required the use of scanners. Not everyone knew about how the EGR system poisons the engine and coke the intake elements, requiring regular disassembly and cleaning (conventionally - every 30 t.km). Not everyone knew that trying to replace the timing belt with the "3S-FE similarity method" results in pistons and valves meeting. Not everyone imagined if there was at least one car service in their city that successfully solved D-4 problems.

Why is Toyota generally valued in Russia (if there are Japanese brands cheaper, faster, more sporty, more comfortable ..)? For "unpretentiousness", in the broadest sense of the word. Unpretentiousness in work, unpretentiousness to fuel, to consumables, to the choice of spare parts, to repair ... You can, of course, buy extracts of high technologies at the price of a normal car. You can choose gasoline carefully and pour a variety of chemicals inside. You can count every cent you save on gasoline - whether the costs of the upcoming repairs will be covered or not (excluding nerve cells). You can train local servicemen in the basics of repairing direct injection systems. You can recall the classic "something has not broken for a long time, when will it finally fall down" ... There is only one question - "Why?"

In the end, buyers' choice is their own business. And the more people get in touch with HB and other dubious technologies, the more customers the services will have. But elementary decency still requires saying - buying a car with a D-4 engine with other alternatives is contrary to common sense.

Retrospective experience allows us to assert that the necessary and sufficient level of reduction of emissions of harmful substances was provided already by classic engines of the Japanese market models in the 1990s or by the Euro II standard in the European market. All that was required was multipoint injection, one oxygen sensor and an underbody catalyst. For many years, such machines worked in a standard configuration, despite the disgusting quality of gasoline at that time, their own considerable age and mileage (sometimes completely exhausted oxygenators needed to be replaced), and getting rid of the catalyst on them was as easy as shelling pears - but usually there was no such need.

The problems began with the Euro III stage and correlated norms for other markets, and then they only expanded - a second oxygen sensor, moving the catalyst closer to the exhaust, switching to "collectors", switching to broadband mixture composition sensors, electronic throttle control (more precisely, algorithms, deliberately worsening the engine response to the accelerator), increasing temperature conditions, debris of catalysts in the cylinders ...

Today, with normal gasoline quality and much fresher cars, the removal of catalysts with re-flashing of Euro V> II type ECUs is massive. And if for older cars in the end it is possible to use an inexpensive universal catalyst instead of an obsolete one, then for the freshest and most "intelligent" cars there is simply no alternative to breaking through the collector and programmatically disabling emission control.

A few words on some purely "ecological" excesses (gasoline engines):
- The exhaust gas recirculation (EGR) system is an absolute evil, as soon as possible it should be muffled (taking into account the specific design and the presence of feedback), stopping the poisoning and contamination of the engine with its own waste.
- Fuel vapor recovery system (EVAP) - works fine on Japanese and European cars, problems arise only on models of the North American market due to its extreme complexity and "sensitivity".
- The Exhaust Air Supply (SAI) system is unnecessary, but also relatively harmless for North American models.

In fact, the recipe for an abstractly better engine is simple - gasoline, R6 or V8, aspirated, cast iron block, maximum safety factor, maximum displacement, distributed injection, minimum boost ... but alas, in Japan this can only be found on cars that are clearly "anti-popular "class.

In the lower segments available to the mass consumer, it is no longer possible to do without compromises, so the engines here may not be the best, but at least "good". The next task is to evaluate motors, taking into account their real application - whether they provide an acceptable thrust-to-weight ratio and in what configurations they are installed (an ideal engine for compact models will be clearly insufficient in the middle class, a structurally more successful engine may not be aggregated with all-wheel drive, etc.) ... And, finally, the time factor - all our regrets about the excellent motors that were discontinued 15-20 years ago does not mean at all that today we need to buy ancient worn-out cars with these engines. So it makes sense to talk only about the best engine in its class and in its time period.

1990s. It is easier to find a few unsuccessful engines among classic engines than to choose the best from a mass of good ones. However, two absolute leaders are well known - 4A-FE STD type "90 in the small class and 3S-FE type" 90 in the middle. In the large class, the 1JZ-GE and 1G-FE type "90 are equally approved.

2000s. As for the third wave engines, kind words can be found only about 1NZ-FE type "99 for the small class, while the rest of the series can only compete with varying success for the title of outsider, even" good "engines are absent in the middle class. pay tribute to 1MZ-FE, which was not bad at all against the background of young competitors.

2010s. In general, the picture has changed a little - at least the 4th wave engines still look better than their predecessors. In the junior class there is still 1NZ-FE (unfortunately, in most cases it is a "modernized" type "03" for the worse). In the senior segment of the middle class, the 2AR-FE performs well. economic and political reasons for the average consumer no longer exist.

However, it is better to look at examples to see how the new engine versions turned out to be worse than the old ones. About 1G-FE type "90 and type" 98 has already been said above, but what is the difference between the legendary 3S-FE type "90 and type" 96? All the deteriorations are caused by the same "good intentions", such as reducing mechanical losses, reducing fuel consumption, and reducing CO2 emissions. The third point refers to the completely insane (but beneficial for some) idea of ​​a mythical fight against mythical global warming, and the positive effect of the first two turned out to be disproportionately less than the resource drop ...

Deteriorations in the mechanical part refer to the cylinder-piston group. It would seem that the installation of new pistons with trimmed (T-shaped in projection) skirts to reduce friction losses could be welcomed? But in practice, it turned out that such pistons begin to knock when shifting to TDC at much lower runs than in the classic type "90. And this knock does not mean noise in itself, but increased wear. It is worth mentioning the phenomenal stupidity of replacing completely floating piston fingers pressed in.

Replacing the distributor ignition with DIS-2 in theory is characterized only positively - there are no rotating mechanical elements, longer coil life, higher ignition stability ... But in practice? It is clear that it is impossible to manually adjust the base ignition timing. The resource of the new ignition coils, in comparison with the classic remote ones, has even dropped. The service life of high-voltage wires has expectedly decreased (now each candle sparks twice as often) - instead of 8-10 years they served 4-6 years. It is good that at least the candles remained simple two-pin, and not platinum.

The catalyst moved from under the bottom directly to the exhaust manifold in order to warm up faster and start working. The result is a general overheating of the engine compartment, a decrease in the efficiency of the cooling system. It is unnecessary to mention the notorious consequences of the possible ingress of crumbled catalyst elements into the cylinders.

Fuel injection instead of pairwise or synchronous became purely sequential in many variants of the "96" type (in each cylinder once per cycle) - more accurate dosage, reduced losses, "ecology" ... In fact, gasoline was now given before entering the cylinder much less time for evaporation, therefore starting characteristics at low temperatures automatically deteriorated.

More or less reliably, we can only talk about the "resource before the bulkhead", when the mass series engine required the first serious intervention in the mechanical part (not counting the replacement of the timing belt). For most classic engines, the bulkhead fell on the third hundred of the run (about 200-250 t.km). As a rule, the intervention consisted in replacing worn or stuck piston rings and replacing the valve stem seals - that is, it was just a bulkhead, and not a major overhaul (the geometry of the cylinders and hone on the walls were usually preserved).

Engines of the next generation often require attention already at the second hundred thousand kilometers, and in the best case, the matter is to replace the piston group (in this case, it is advisable to replace parts with modified ones in accordance with the latest service bulletins). With a noticeable oil fumes and the noise of piston shifting on runs over 200 t.km, you should prepare for a major repair - the strong wear of the liners leaves no other options. Toyota does not provide for the overhaul of aluminum cylinder blocks, but in practice, of course, the blocks are overheated and bored. Unfortunately, reputable companies that really perform the overhaul of modern "disposable" engines with high quality and at a high professional level in all countries can really be counted on one hand. But vigorous reports of successful reloading today come already from mobile collective farm workshops and garage cooperatives - what can be said about the quality of work and the resource of such engines is probably understandable.

This question is posed incorrectly, as in the case of "the absolute best engine". Yes, modern motors cannot be compared with classical ones in terms of reliability, durability and survivability (at least, with the leaders of past years). They are much less maintainable mechanically, they become too advanced for an unqualified service ...

But the fact is that there is no longer an alternative to them. The emergence of new generations of motors must be taken for granted and every time you need to learn to work with them anew.

Of course, car owners should in every possible way avoid individual unsuccessful engines and particularly unsuccessful series. Avoid motors of the earliest releases, when the traditional "customer run-in" is still underway. If there are several modifications of a particular model, you should always choose a more reliable one - even if you compromise either finances or technical characteristics.

P.S. In conclusion, we cannot but thank Toyot "y for the fact that once she created engines" for people ", with simple and reliable solutions, without the frills inherent in many other Japanese and Europeans. And let the owners of cars from" advanced and advanced "manufacturers they scornfully called them kondovy - so much the better!

"The simplest Japanese engine"

Engines 5A, 4A, 7A-FE
The most common and by far the most widely repaired Japanese engine is the (4,5,7) A-FE series. Even a novice mechanic, diagnostician is aware of possible problems with 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 fixed by the control unit code 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, and it makes no sense to install a used one (their operating life 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 diagnostic connector block, 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. In the event of a break in the measuring element of the sensor, 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 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 variable resistor of 1kΩ in its circuit, or a constant 300Ω, for further verification. By changing the sensor readings, it is easy to control the change in speed at different temperatures.

Throttle position sensor

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 registers error 41. When replacing a new sensor, it is necessary to adjust 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

MAP absolute pressure sensor

This sensor is the most reliable ever 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 increases 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 increases sharply to 3.5-5 ms. During gas re-gasings, a black exhaust appears, the candles are planted, there is a shaking 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. Revolutions. 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 you experience symptoms of speed limitation 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 engine operation and an increase in 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 above one percent will indicate the need to flush the injectors (with the correct 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.

Idle valve, IACV

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). There are no tests for changing the speed in scanners when diagnosing this motor. You can assess 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 the Х.Х. 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 "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, 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 pulled out of the wells with force, 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 wire thickness 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.

" Subtle "faults
On modern engines 4A, 7A, the Japanese changed the firmware of the control unit (apparently for faster engine warm-up). 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 a temperature of 75-80 degrees. And as a result, constant warming up speed (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 different types of oils are not compatible 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 dipstick handle. 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 the wear of the valve stem seals is to blame, 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 garage rodents living in the air filter housing. Which speaks of their utter disregard for the car.

Fuel filter also 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 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
Until 1998, the control units did not have serious enough problems during operation.

The blocks had to be repaired only because of the "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 terminal for checking, or for wire continuity. 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" carry out the belt replacement procedure on their own (although this is not correct, they cannot properly tighten the crankshaft pulley). The mechanics will make a quality replacement within two hours (maximum). If the belt breaks, the valves do not meet the piston and the engine will not be fatally destroyed. Everything is calculated to the smallest detail.

We tried to tell you about the most common problems on engines of this series. The engine is very simple and reliable, and under the condition of very tough operation on "water-iron gasoline" and dusty roads of our great and mighty Motherland and "avos" mentality of the owners. Having endured all the bullying, it continues to delight to this day with its reliable and stable work, having won the status of the best Japanese engine.

Successful repairs to all.

Vladimir Bekrenev
Khabarovsk

Andrey Fedorov
Novosibirsk city