Toyota direct injection system D-4
I had to see the first 3S-FSE engine under repair in early 2001. It was a Toyota Vista. I changed the valve stem seals and simultaneously studied the new engine design. The first information about him appeared later in 2003 on the Sakhalin site at Kucher Vladimir Petrovich. The first successful repairs gave an indispensable experience for working with this type of engine, which now will not surprise anyone. Then, I had little idea of what miracle I was dealing with. The engine was so revolutionary that many repairmen simply refused repairs. Using fuel injection pump, high pressure, two catalysts, an electronic throttle, an EGR control stepper motor, tracking the position of additional dampers in the intake manifold, VVTi system, and an individual ignition system, the developers showed that a new era of economical and environmentally friendly engines has come.
The photos show a general view of the engines 3S-FSE, 1AZ-FSE, 1JZ-FSE.
A schematic block diagram of a direct injection engine using the example of 1AZ-FSE is as follows.
The following important systems and their elements, which most often have defects, should be noted..
Fuel supply system: submersible electric pump in the tank with a fuel intake grid and a fuel filter at the outlet, a high pressure fuel pump mounted on the cylinder head with a camshaft drive, a fuel rail with a pressure reducing valve.
Synchronization system: crankshaft and camshaft sensors. Control system:
Sensors: mass air flow, coolant temperature and intake air, detonation, gas pedal and throttle position, pressure in the intake manifold, fuel pressure in the ramp, heated oxygen sensors;
Actuators: ignition coils, nozzle control unit and nozzles themselves, ram pressure control valve, vacuum solenoid for damper control in the intake manifold, VVT-i clutch control valve. This is not the whole list, but this article does not claim to be a complete description of direct injection engines. The above diagram naturally corresponds to the structure of the table of fault codes and current data. If there are codes in the memory, you need to start with them. Moreover, if there are a lot of them, it makes no sense to analyze them, it is necessary to rewrite, erase and send the owner on a test drive. If the control lamp lights up, read and analyze the narrower list again. If not, go directly to the analysis of current data..
When diagnosing an engine, the scanner provides a date of the order of (80) parameters for assessing the condition and analyzing the operation of sensors and engine systems. It should be noted that a major drawback of 3S-FSE is the lack of a parameter in the date – “fuel pressure”. But, despite this, the date is very informative and, with proper understanding, accurately reflects the operation of sensors and systems of the engine and automatic transmission.
For example, let’s look at one correct date and several fragments of the date with problems with the 3S-FSE motor
On this fragment of the date we see the normal injection time, ignition angle, vacuum, engine speed at idle, engine temperature, air temperature. Throttle position and idle warning.
From the following picture you can evaluate the fuel correction, oxygen sensor reading, vehicle speed, EGR motor position.
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Next, we see the inclusion of a starter signal (important at startup), the inclusion of an air conditioner, electric load, power steering, brake pedal, automatic transmission position.
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Then, the inclusion of the clutch of the air conditioner, the valve of the system for collecting fuel vapor, the VVTi valve, overdrive, solenoids in the automatic transmission
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Many parameters are presented to evaluate the operation of the damper unit (electronic throttle)
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As you can see by the date, you can easily evaluate the work and check the operation of almost all the main sensors and systems of the engine and automatic transmission. If you line up the readings, you can quickly assess the condition of the engine and solve the problem of incorrect operation.
The following snippet shows an extended fuel injection time. Date Received by DCN-PRO Scanner.
And in the next fragment, an open air temperature sensor break (-40 degrees), and an abnormally high injection time (1.4 ms with a standard of 0.5-0.6 ms) on a warm engine.
Abnormal correction makes you wary and check the first debt of the presence of gasoline in the oil.
The control unit makes the mixture darker (-80%)
The most important parameters that adequately reflect the state of the engine are lines with indications of long and short fuel corrections; oxygen sensor voltage; vacuum in the intake manifold; engine rotation speed (revolutions); EGR motor position; throttle position in percent; ignition timing, and fuel injection time. For a quicker assessment of the engine operating mode, lines with these parameters can be arranged on the scanner display. Below in the photo is an example of a fragment of the engine operating date in normal mode. In this mode, the oxygen sensor switches, the vacuum in the collector is 30 kPa, the throttle is open by 13%; lead angle of 15 degrees. EGR valve is closed. This arrangement and selection of parameters will save time on checking the condition of the engine.
Here are the main lines with the parameters for the analysis of the engine.
And here is the date in lean mode. When the switch to the lean mode of operation, the throttle opens, EGR opens, the oxygen sensor voltage is about 0, a vacuum of 60 kPa, an advance angle of 23 degrees. This is the lean mode.
For comparison, a fragment of the depletion mode date taken by the DCN-PRO scanner
It is important to understand that if the engine works correctly, then subject to certain conditions, it must go into lean mode. The transition occurs when the engine is fully warmed up and only after rebasing. Many factors determine the process of switching the engine to lean mode. When diagnosing, it is necessary to take into account the uniformity of fuel pressure, and the pressure in the cylinders, and the intake manifold planting, and the correct operation of the ignition system.
Now let’s see the date from the 1АZ-FSE engine. The developers corrected the missed errors, there is a line with pressure. Now you can easily evaluate pressure in various modes.
In the next photo we see in normal mode the fuel pressure is 120kg.
In lean mode, the pressure is reduced to 80 kg. And the lead angle is set to 25 degrees.
The date from the 1JZ-FSE engine is practically no different from the date of the 1AZ-FSE. The only difference is that when lean, the pressure is reduced to 60-80 kg. In normal mode, 80-120kg. For all the completeness of the dates that the scanner issues, in my opinion, one very important parameter is missing for assessing the pump’s longevity. This is a parameter of the pressure regulator valve. By the duty cycle of the control pulses, one can evaluate the “strength” of the pump. Nissan has such a parameter in the date. Below are fragments of the date from the VQ25 DD engine.
Here you can clearly see how the pressure is regulated when the control pulses on the pressure regulator change.
The following photo shows a fragment of the date (main parameters) of the 1JZ-FSE engine in lean mode.
It should be noted that the 1JZ-FSE engine is able to work without high pressure (unlike 4-cylinder counterparts), while the car is able to move around. However, in the event of any serious, but not very serious interference (malfunctions), the transition to the depleted mode will not occur. Dirty damper, problems in sparking, fuel supply, gas distribution do not allow the transition. At the same time, the control unit lowers the pressure to 60 kg.
On this fragment, you can see the absence of the transition and the slightly open shutter, which indicates the contamination of the channel x \ x. There will be no depleted regime. And for comparison, a piece of date in normal mode.
On the first engine with HB, the designers used collapsible injectors. The fuel rail has a 2-story design of different diameters. This is necessary to equalize the pressure. In the following photo, high-pressure fuel cells3S-FSE.
Fuel rail, fuel pressure sensor on it, emergency pressure relief valve, injectors, high pressure fuel pump and main pipes.
Here is the fuel rail of the 1AZ-FSE engine, it has a simpler design with one through hole.
And the following photo shows the fuel rail from the 1JZ-FSE engine. The sensor and valve are located side by side; injectors differ from 1AZ-FSE only in the color of plastic windings and performance.
In engines with HB, the operation of the first pump is not limited to 3.0 kilograms. Here, the pressure is slightly higher than about 4.0 – 4.5 kg to ensure proper nutrition of the injection pump in all operating modes. Measurement of pressure during diagnosis, can be done with a manometer through the inlet port directly to the injection pump.
When the engine starts, the pressure should “build up” to its peak in 2-3 seconds, otherwise the start will be long or it will not be at all. The photo below measures the pressure on the 1AZ-FSE engine
In the next photo, we measured the pressure of the first pump on the 3S-FSE engine (pressure is below normal, the first pump needs to be replaced.)
Since engines were produced for the Japanese domestic market, the degree of fuel purification does not differ from conventional engines. First screen mesh in front of the pump.
For comparison, the dirty and new mesh of the first 1AZ-FSE engine pump. In case of such contamination, the mesh must be changed or cleaned with a carbcliner. Gasoline deposits pack the net very tightly, the pressure of the first pump decreases.
Then the second fine filter engine (3S-FSE) (by the way, he does not hold water).
When replacing the filter, cases of improper assembly of the fuel cartridge are not uncommon. This causes a loss of pressure and does not start..
The photographs below show for comparison the new and clogged input grids, filter options from the 1AZ-FSE engine.
It looks like a fuel filter in the context after 15 thousand mileage. A very decent barrier to gas debris. With a dirty filter, the transition to the depleted mode is either very long, or it does not exist at all.
And the last screen is the fuel filter mesh at the inlet of the high pressure fuel pump. From the first pump, fuel with a pressure of about 4 Atm enters the injection pump, then the pressure rises to 120 Atm and enters the fuel rail to the injectors. The control unit evaluates the pressure from the pressure sensor signal. The ECM adjusts the pressure using the regulator valve on the high pressure fuel pump. In the event of an emergency increase in pressure, the pressure reducing valve in the rail is activated. So briefly organized the fuel system on the engine. Now more about the components of the system and about the methods of diagnosis and verification.
The high-pressure fuel pump has a fairly simple design. Reliability and longevity of the pump depend (like much on the Japanese) on various small factors, in particular on the strength of the rubber seal and the mechanical strength of the pressure valves and plunger. The structure of the pump is ordinary and very simple. There are no revolutionary solutions in the design. The basis is a plunger pair, an oil seal separating gasoline and oil, pressure valves and an electromagnetic pressure regulator. The main link in the pump is a 7mm plunger. As a rule, the plunger does not wear out very much in the working part (unless abrasive gasoline is used, of course). The main problem in the pump is the wear of the rubber gland (the life of which is determined by no more than 100 thousand kilometers). This run, of course, underestimates the reliability of the engine. The pump itself costs insane money 18-20 thousand rubles (Far East). On the 3S-FSE engines, three different high pressure fuel pumps were used, one with an upper pressure regulator valve and two with a side.
The following are photos of the pump, and details of its components.
Disassembled pump, pressure valves, pressure regulator, oil seal and plunger, oil seal seat. 3S-FSE engine disassembly pump.
When operating on low-quality fuel, corrosion of the pump parts occurs, which leads to accelerated wear and pressure loss. The photo shows signs of wear in the core of the pressure valve and the thrust washer of the plunger.
Method for diagnosing a pump by pressure and leakage of an oil seal.
On the site http://forum.autodata.ru I already laid out the method of checking pressure by pressure sensor voltage. Just to remind you of some of the details. To control the pressure you have to use the readings taken from the electronic pressure sensor. The sensor is installed at the end of the fuel rail. Access to it is limited and therefore it is easier to take measurements on the control unit. For Toyota Vista and Nadi, this is the conclusion B12 – the engine ECU (wire color is brown with a yellow stripe) The sensor is powered by a voltage of 5v. At normal pressure, the sensor readings vary in the range (3.7-2.0 V.) – signal output to the PR sensor. The minimum readings at which the engine is still capable of operating at x \ x -1.4 volts. If the sensor readings are below 1.3 volts for 8 seconds, the control unit will register DTC P0191 and stop the engine.
Correct sensor readings at x \ x -2.5 in. With a depletion of 2.11 in
The photo below shows an example of pressure measurement. Pressure below normal – the cause of loss of leaks in the pressure valves of the injection pump.
It is necessary to register the leak of gasoline into the oil using gas analysis. Indications of the level of CH in oil should not exceed 400 units on a warm engine. Ideal option 200-250 units.
The gas analyzer probe is inserted into the oil filler neck when checking, and the neck itself is closed with a clean rag.
Abnormal indications level CH-1400 units – the pump requires replacement. When the gland flows, a very large minus correction will be registered in the date.
And with full warming up, with a leaking stuffing box, the engine speed will jump strongly at x \ x, and when the engine is rebased, it will periodically stall. When the crankcase is heated, gasoline evaporates and again enters the intake manifold through the ventilation line, further enriching the mixture. An oxygen sensor registers a rich mixture, and the control unit tries to become poor. It is important to understand that in this situation, together with replacing the pump, it is necessary to change the oil with the engine flushing.
In the following photo, fragments of measuring the level of CH in oil (overestimated values)
Pump repair methods.
The pressure in the pump disappears very rarely. Pressure loss occurs due to the development of a plunger washer, or due to sandblasting of a pressure regulating valve. From the practice, the plungers practically did not wear out in the working area. Often it is necessary to condemn the pump due to problems with the oil seal, which, when erased, begins to let fuel into the oil. Checking the presence of gasoline in the oil is not difficult. It is enough to measure SN in the oil filler neck on a warm running engine. As noted earlier, the readings should be no more than 400 units. Native oil seal is deposited in the pump body. This is important when replacing an old stuffing box..
Both the inside and the outside are involved in the work. Viktor Kostyuk from Chita suggested changing the seal to a cylinder with a ring.
This idea belongs entirely to him. Trying to reproduce Victor’s oil seal, we encountered some difficulties. Firstly, the old plunger has a noticeable wear in the area of the gland. It is 0.01mm. This was enough to cut the gum of the new oil seal. As a result, gasoline was allowed to pass into the oil.
Secondly, we still cannot find the best option for the inner diameter of the ring. And the width of the groove. Thirdly, we are concerned about the need for a second groove. There are two rubber cones in the stuffing box. If you correctly calculate all the mechanical components, friction, then it will be possible to extend the life of the pump for an indefinite period. And save customers from the predatory prices for a new pump.
Repair of the mechanical part of the pump consists in grinding pressure valves and washers against signs of wear. Pressure valves of the same size, they are easily rubbed with any finishing abrasive for grinding valves.
In the photo, an enlarged valve. Radial and working well visible.
I met one dubious kind of pump repair. Repairmen glued glue on the main pump seal butt part of the seal from the 5A engine. Outwardly, everything was beautiful, but only the gasket did not hold the reverse part of the seal. Such repairs are not permitted and may result in engine fire. The photo shows a glued seal.
The next generation of 1AZ and 1JZ engine pumps is slightly different from its predecessor.
The pressure regulator has been changed, only one pressure valve has been left and it is not collapsible, a spring has been added to the stuffing box, the pump casing has become somewhat smaller. Failures and leaks in these pumps are much less, but still, the service life is not long.
Further on the photos – the appearance of the pump and the oil seal with a spring ring, control valve, plunger.
Fuel rail, injectors and emergency relief valve.
On the 3S-FSE engines, the Japanese first used a collapsible nozzle. A conventional injector capable of operating at a pressure of 120 kg. It should be noted that the massive metal case and grooves under the grip meant long-term use and maintenance.
The rail with injectors is located in a remote place under the intake manifold and noise protection.
But nevertheless, the dismantling of the entire assembly can be easily carried out from below the engine, without much effort. The only problem is to swing the soured injector with a specially made key. 18 mm key with sharpened edges. All work has to be done through a mirror due to inaccessibility.
Next, in the photo, a general view of the dismantled injector (s) of the 3S-FSE engine, view of a dirty nozzle (spray).
As a rule, during dismantling, traces of nozzle coking are always noticeable. This picture can be seen when using an endoscope by looking at the cylinders..
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