The ideal ratio of gasoline and air , in which the entire mixture burns completely is considered stoichiometric (ideal). The engine works well if the gasoline + air mixture burns well. The mixture burns well if it is optimal. The mixture is optimal if 1 g of gasoline is supplied to 14.7 g of air. The optimal fuel-air mixture burns as quickly as possible and gives the right amount of energy without unnecessary heat. The main thing in the optimal formation of the fuel-air mixture is the DMRV.
AFR is the ratio of air to fuel in an engine's combustion chamber.
Ideal ratio fuel and air for gasoline engines(stoichiometric mixture) = 14.7/1 (AFR) for petrol/diesel.
14.7 g of air per 1 g of gasoline.
Each fuel needs its own fuel/air ratio.
Lean or rich mixture.The air-fuel mixture can be lean or rich.
On one paid Pilot, there didn’t seem to be any problems, the automatic transmission generally switches evenly. And I recently installed Vagovsky, I think the native is better, and the box sometimes blunts from the first to the second. I'm going to change this device TPS Pilot. Works better with it smoothly. It’s a nice thing to pedal from the intersection on it 1 2 3 perfectly switch themselves in time. TPS Pilot contactless
Poor mixture (injector), signs and consequences
Mixture setting
While driving Pilot see in real time which mixture is lean or rich.
Poor mixture signs- a stalling engine, more than 14.7 g of air, ignites faster and is accompanied by excessive heating .. Such a mixture is prone to detonation, at low speeds it is not scary. At full load, mixture 14 is already considered hazardous. Doing the whole system on a mixture of 14.7 is not reasonable. At low revs, this will not be enough for acceleration, and at higher revs, you will simply catch detonation.
Poor mixture consequences- at high speeds, with a full load, the level of detonation reaches catastrophic consequences. Piston burnt or fused, valves or spark plugs burnt out. Rising temperatures and loss of power are the simplest things that can happen to an engine when knocking. Usually it is a jammed and overheated motor.
On VAF "e, the consumption was about 25 liters in the city, and on a normally configured converter,15 l in the city, so consider the benefit. I thank smart, honest, temperamental for feedback and dissemination of information.
Rich mixture (injector), signs and effects
Mixture setting
richmix signs
- Fuel consumption has risen sharply.
- Exhaust gases are black or grey.
- Air is less than 14.7g, safer and more reliable for the engine.
A rich mixture of consequences - long-term operation of the engine on a rich mixture can lead to piston failure and failure of the spark plugs.
While driving Pilot records the operation of the oxygen sensor and the air flow sensor. At the same time, it is possible see in real time whether the mixture is lean or rich.
In the end, I want to thank the guys who are involved in this project, I hope their thing will serve me for a long time. By the way, this version is suitable for both mechanics and automatic transmission, I have an automatic transmission, so for me it is a gift of fate I would say! TPS Pilot contactless I thank smart, honest, temperamental for feedback and dissemination of information.
Reasons for the formation of a rich mixture of an injection engine
- injectors deliver too much fuel
- air filter clogging
- poor throttle performance
- fuel pressure regulator malfunction
- air flow sensor malfunction
- evaporative emission system malfunction
- incorrect operation of the economizer.
It works on cars that do not work on traditional methods such as spacers for lambda probes and circuits such as a capacitor + resistor. Electronic emulator Lambda probe Catalyst 2-channel Pilot .. For engines with two catalysts and two additional oxygen sensors - you need to buy one emulator. Support for lambda probes with offset signal ground. ElectI thank smart, honest, temperamental for feedback and dissemination of information.
lambda sensor
The readings of the lambda sensor are the ratio of the current mixture to the ideal one.
Example: current mixture - air 12.8 g. Lambda sensor readings 0.87=12.8 / 14.7
The ECU takes into account the readings of the lambda sensor only with uniform movement.
When accelerating, braking and warming up, the ECU does not take into account the readings of the lambda sensor and works according to the program.
When tuning, you need to catch the transition from a lean mixture to a rich one. From this point to do a little richer.
In this case, the lambda sensor jumps from 0 to 1. The transition point is approximately 0.45.
For other modes of engine operation, a broadband sensor is used.
The reached maximum speed - about 200-210 km / h did not measure the dynamics, but in the test run they somehow crossed with the E39 M50B20, well, they lit it - it turned out that he is not my rival in terms of dynamics neither from the bottom, nor at three-digit speeds. The actual consumption fluctuates around 11l of the 92nd. Replacing the flow meter with a non-native one without firmware! + mix setting Converter Pilot + BLUETOOTH I thank smart, honest, temperamental for feedback and dissemination of information.
Air is central to optimal education fuel-air mixture is DMRV
Accurate injection of gasoline is easier than precise injection of air. Errors in the calculation of the incoming air lead to problems in the operation of the engine. The errors will be smaller if the air flows in a uniform flow. Flow uniformity is created:
- smooth duct walls
- smooth turns of the air duct (1- 2)
- the absence of pulsations and swirls (remove everything that leads to this from the flow, especially the "nulevik" filter)
If everything is in order along the gasoline supply line, then the main thing in the optimal formation of the mixture is the DMRV (mass air flow sensor). Based on its signals, the ECU supplies gasoline. At the exit there is a "controller" (lambda probe) and "sniffs" the exhaust gases. It determines what is a lot - gasoline or air and informs the ECU. The ECU adjusts the fuel supply.
When you change the flow meter to a non-original one (VAF to MAF), then:
- constructively change the direction for the air flow - this is very important
- should solve the problem with the inlet air temperature sensor (if it is missing, it will not start in winter)
- and most importantly, put a "translator" for the ECU so that the ECU understands which signal of the old flow meter corresponds to the signal of the new flow meter (these are devices such as the Pilot VAF / MAF converter, MAF Emulator 3, "Winners Sensor" (Winners)).
- after all changes, the mixture needs to be adjusted.
I got a little tired of fussing with the flow meter, or as it is often called a shovel. Climbing through my favorite lancruiser.ru I came across a link Pilot Engineering.
I read their local forum and came to the conclusion that this is a super-duper-mega-PANACEA! The advantage of this converter is its customization flexibility. He even supports ShPLZ! Converter Pilot + BLUETOOTH - mixture setting I thank smart, honest, temperamental for feedback and dissemination of information.
Inlet air temperature sensor
There are two ways to solve the problem of the intake air temperature sensor:
- put a resistor instead of it and the ECU will think that you have summer +20 all year round
- open the VAF and remove the sensor from it, and install it in the intake manifold (according to the results, this option is better)
Engine
The engine has several modes of operation:
- idle and warm up
- uniform motion
- acceleration, braking - smooth
- acceleration (WOT), braking - sharp
neutral, gearbox not connected
idling with the box connected, standing at a traffic light
Harsh acceleration, braking - this is a sharp effect on the air flow (throttle). We get ripples and swirls.
Sharp acceleration - a lot of air, but little gasoline. Add gasoline in an emergency - the accelerator pump should turn on.
Hard braking - little air, a lot of gasoline. Add air in an emergency - an additional air supply channel should open.
For both modes - the "retarder" of the throttle opening should work. The throttle valve assembly is equipped with a smooth gas release system - a purely mechanical damper system that slows down not abruptly, but smoothly when the accelerator pedal is released. It seems that it was precisely its adjustment that made it possible, at least now it has been verified that this is the case, to ensure a smooth decrease in engine speed without jittering.
Solving the problem with poor engine performance:
- check everything related to the supply of gasoline
- check everything related to the air supply
Action algorithm:
- Count errors.
- If item 1 is not fulfilled, then we logically determine which is more gasoline or air. Or the smell from the exhaust pipe. The color of the candles.
- Determined - gasoline is low.
- We go along the line of supply of gasoline:
- Mechanics(part wear, deformation, accelerator pump, gas pump, fuel filter, injectors, fuel pump mesh, gas tap, small passage hole inside the tap. Corrected: by replacing the tap or drilling.),
- electrician(contacts, wires, correct connection),
- time trigger(injector keys, ignition angle, distributor, candles),
- temperature triggered-worse for hot (some part heated up and the gap between it and the neighboring one decreased, friction appeared or the gap increased and there was no contact - the timing belt, the tension roller just dangled, the camshafts were out of sync with the crankshaft and the engine stalled. , bypass roller, spring, DTVV, DTOZH)
5. Air - not enough. I put the pilot, I'm quite satisfied, the machine is unrecognizable. Plus converter is the ability to adjust to changes with the engine. You can still diagnose the death of two sensors (DMRV and LZ), which is also necessary. All in all this item is worth the money, I have already seen in practice. Now it has become much more pleasant for me to ride without all sorts of poddergush and floating xx. The car goes as it was intended and it certainly pleases me! And, believe me, no more or less, and it works with a bang! Converter Pilot + BLUETOOTH - mixture setting I thank smart, honest, temperamental for feedback and dissemination of information.
Setting the air/fuel ratio (AFR)
The purpose of tuning is to get maximum power and maximum torque during hard acceleration, with moderate consumption in city and on the highway.
There are two ways to set up a mixture:
- trimming resistor - a limited range ("Sensor Winners" (Winners)). Before that, be sure to set the basic settings through VAGCOM.
- using software (MAF Emulator 3, Pilot VAF/MAF). The software from MAF Emulator 3 is configured for broadband lambda, and the software from the Pilot VAF / MAF converter is configured for conventional lambda.
Set up step by step:
- XX setting,
- further adjustment of overclocking.
- The most correct is the uphill mode.
- If you can tune the engine as efficiently as possible in this mode, then consider that the tuning was a success. Never set the entire rpm range in neutral.
The higher the speed, the richer the air-fuel mixture, and the earlier the ignition angle.
Don't forget before you start set the mechanical ignition timing according to the stroboscope.
Electronic emulator+ BLUETOOTH Lambda Probe Catalyst 2 Channel Pilot 1. There is a setting for emulation parameters
2. There is logging - recording of all emulation parameters while the car is moving
3. Engine type: any 4. Installation: open circuit
5. Programming: Yes
6. Diagnostics saved
7. Before being sent to the client, it undergoes a mandatory parameter setting and performance test.
8. Support Euro 3, 4, 5, 6
9. No intervention in the software part of the computer
10. Warranty - 1 year
Elect
ron blende Pilot + BLUETOOTH.
I thank smart, honest, temperamental for feedback and dissemination of information.
Let's turn our attention to the output voltage of the B1S1 sensor on the scanner screen. The voltage fluctuates around 3.2-3.4 volts.
The sensor is able to measure the actual air-fuel ratio over a wide range (from lean to rich). The output voltage of the sensor does not indicate rich/lean as a conventional oxygen sensor does. The wideband sensor informs the control unit of the exact fuel/air ratio based on the oxygen content of the exhaust gases.
The sensor test must be carried out in conjunction with the scanner. However, there are a couple more ways to diagnose. The outgoing signal is not a voltage change, but a bidirectional current change (up to 0.020 amps). The control unit converts the analog current change into voltage.
This change in voltage will be displayed on the scanner screen.
On the scanner, the sensor voltage is 3.29 volts with an AF FT B1 S1 mixture ratio of 0.99 (1% rich), which is almost ideal. The block controls the composition of the mixture close to stoichiometric. The voltage drop of the sensor on the scanner screen (from 3.30 to 2.80) indicates the enrichment of the mixture (oxygen deficiency). An increase in voltage (from 3.30 to 3.80) is a sign of a lean mixture (excess of oxygen). This voltage cannot be taken with an oscilloscope, as with a conventional O2 sensor.
The voltage at the sensor contacts is relatively stable, and the voltage at the scanner will change in the event of a significant enrichment or depletion of the mixture, recorded by the composition of the exhaust gases.
On the screen, we see that the mixture is enriched by 19%, the sensor readings on the scanner are 2.63V.
These screenshots clearly show that the block always displays the real state of the mixture. The value of the parameter AF FT B1 S1 is the lambda.
|
INJECTOR.................2.9ms ENGINE SPD..............694rpm AFS B1 S1................ 3.29V SHORT FT #1............. 2.3% AF FT B1 S1............. 0.99 What type of exhaust? 1% rich |
Snapshot #3 INJECTOR.................2.3ms ENGINE SPD............1154rpm AFS B1 S1................ 3.01V LONG FT #1................4.6% AF FT B1 S1............. 0.93 What type of exhaust? 7% rich |
|
Snapshot #2 INJECTOR.................2.8ms ENGINE SPD............1786rpm AFS B1 S1................ 3.94V SHORT FT #1.............. -0.1% LONG FT #1............... -0.1% AF FT-B1 S1............... 1.27 What type of exhaust? 27% lean |
Snapshot #4 INJECTOR.... 3.2ms ENGINE SPD..............757rpm AFS B1 S1................ 2.78V SHORT FT #1.............. -0.1% LONG FT #1................4.6% AF FT B1 S1............. 0.86 What type of exhaust? 14% rich |
Some OBD II scanners support the option of broadband sensors on the screen, displaying voltage from 0 to 1 volt. That is, the factory voltage of the sensor is divided by 5. The table shows how to determine the mixture ratio from the sensor voltage displayed on the scanner screen
|
mastertech Toyota 2.5 volts 3.0 volts 3.3 volts 3.5 volts 4.0 volts |
p style="text-decoration: none; font-size: 12pt; margin-top: 5px; margin-bottom: 0px;" class="MsoNormal"> OBD II Scan Tools 0.5 volts 0.6 volts 0.66 volts 0.7 volts 0.8 volts |
Air:Fuel Ratio 12.5:1 14.0:1 14.7:1 15.5:1 18.5:1 |
Pay attention to the top graph, which shows the voltage of the wideband sensor. It is almost all the time about 0.64 volts (multiply by 5, we get 3.2 volts). This is for scanners that do not support wideband sensors and are running EASE Toyota software.
The device and principle of operation of a broadband sensor.
The device is very similar to a conventional oxygen sensor. But the oxygen sensor generates voltage, and the broadband generates current, and the voltage is constant (voltage changes only in the current parameters on the scanner).
The control unit sets a constant voltage difference across the sensor electrodes. These are fixed 300 millivolts. The current will be generated to hold these 300 millivolts as a fixed value. Depending on whether the mixture is lean or rich, the direction of the current will change.
These figures show the external characteristics of a broadband sensor. The current values are clearly visible at different compositions of the exhaust gas.
On these oscillograms: the upper one is the current of the sensor heating circuit, and the lower one is the control signal of this circuit from the control unit. Current values greater than 6 amperes.
Testing of broadband sensors.
Four-wire sensors. Heating is not shown in the figure.
The voltage (300 millivolts) between the two signal wires does not change. Let's discuss 2 testing methods. Since the operating temperature of the sensor is 650º, the heating circuit must always be running during testing. Therefore, we disconnect the sensor connector and immediately restore the heating circuit. We connect a multimeter to the signal wires.
Now we will enrich the mixture at XX with propane or by removing the vacuum from the vacuum fuel pressure regulator. On the scale, we should see a change in voltage as when a conventional oxygen sensor is working. 1 volt is the maximum enrichment.
The following figure shows the reaction of the sensor to the lean mixture, by turning off one of the nozzles). The voltage is then reduced from 50 millivolts to 20 millivolts.
The second test method requires a different multimeter connection. We turn on the device in a line of 3.3 volts. We observe the polarity as in the figure (red +, black -).
Positive current values indicate a lean mixture, negative values indicate a rich mixture.
When using a graphical multimeter, this is the current curve (we initiate a change in the composition of the mixture with a throttle valve). Vertical scale current, horizontal time
This graph shows the operation of the engine with the injector turned off, the mixture is lean. At this time, the scanner displays a voltage of 3.5 volts for the sensor under test. A voltage above 3.3 volts indicates a lean mixture.
Horizontal scale in milliseconds.
Here the nozzle is turned on again and the control unit tries to reach the stoichiometric composition of the mixture.
This is how the current curve of the sensor looks like when opening and closing the throttle from a speed of 15 km / h.
And such a picture can be reproduced on the scanner screen to evaluate the operation of a broadband sensor using the parameter of its voltage and the MAF sensor. We pay attention to the synchronism of the peaks of their parameters during operation.
You probably know that your car has an oxygen sensor (or even two!) ... But why is it needed and how does it work? FAQs are answered by Stefan Verhoef, DENSO Product Manager (Oxygen Sensors).
Q: What is the job of an oxygen sensor in a car?
O: Oxygen sensors (also called lambda probes) help you monitor your vehicle's fuel consumption, which helps reduce harmful emissions. The sensor continuously measures the amount of unburned oxygen in the exhaust gases and transmits this data to the electronic control unit (ECU). Based on this information, the ECU adjusts the fuel-to-air ratio of the air-fuel mixture entering the engine, which helps the catalytic converter (catalyst) work more efficiently and reduce the amount of harmful particles in the exhaust gases.
Q: Where is the oxygen sensor located?
O: Every new car and most cars made after 1980 are equipped with an oxygen sensor. Typically, the sensor is installed in the exhaust pipe before the catalytic converter. The exact location of the oxygen sensor depends on the type of engine (V or in-line) and the make and model of the vehicle. To determine where the oxygen sensor is located in your vehicle, refer to the owner's manual.
Q: Why does the air-fuel mixture need to be constantly adjusted?
O: The air-fuel ratio is critical because it affects the efficiency of the catalytic converter, which reduces carbon monoxide (CO), unburned hydrocarbons (CH) and nitrogen oxide (NOx) in the exhaust gases. For its effective operation, a certain amount of oxygen in the exhaust gases is necessary. The oxygen sensor helps the ECU determine the exact air-fuel ratio of the mixture entering the engine by providing the ECU with a rapidly changing voltage signal that changes according to the oxygen content in the mixture: either too high (lean) or too low (rich). The ECU reacts to the signal and changes the composition of the air-fuel mixture entering the engine. When the mixture is too rich, fuel injection is reduced. When the mixture is too lean, it increases. The optimal air-fuel ratio ensures complete combustion of the fuel and uses almost all of the oxygen in the air. The remaining oxygen enters into a chemical reaction with toxic gases, as a result of which harmless gases exit the neutralizer.
Q: Why do some cars have two oxygen sensors?
O: Many modern cars, in addition to the oxygen sensor located in front of the catalyst, are also equipped with a second sensor installed after it. The first sensor is the main one and helps the electronic control unit regulate the composition of the air-fuel mixture. The second sensor, installed after the catalyst, monitors the efficiency of the catalyst by measuring the oxygen content in the exhaust gases at the outlet. If all the oxygen is taken up by the chemical reaction between the oxygen and the pollutants, then the sensor generates a high voltage signal. This means that the catalyst is working properly. As the catalytic converter wears out, some of the harmful gases and oxygen cease to participate in the reaction and leave it unchanged, which is reflected in the voltage signal. When the signals become the same, this will indicate a failure of the catalyst.
Q: What are the sensors?
ABOUT: There are three main types of lambda sensors: zirconia sensors, air-fuel ratio sensors, and titanium sensors. All of them perform the same functions, but they use different ways of determining the ratio "air-fuel" and different outgoing signals for transmitting the measurement results.
The most widespread technology is based on the use zirconia sensors(both cylindrical and flat types). These sensors can only determine the relative value of the coefficient: above or below the fuel-air ratio of the lambda coefficient of 1.00 (ideal stoichiometric ratio). In response, the engine ECU gradually changes the amount of fuel injected until the sensor begins to indicate that the ratio has reversed. From this point on, the ECU again begins to correct the fuel supply in the other direction. This method allows you to slowly and continuously "float" around the lambda factor of 1.00, while not allowing you to maintain an exact factor of 1.00. As a result, under changing conditions, such as hard acceleration or braking, zirconium oxide sensor systems are under-fueled or over-fueled, resulting in reduced catalytic converter efficiency.
Air-fuel ratio sensor shows the exact ratio of fuel and air in the mixture. This means that the engine ECU knows exactly how much this ratio differs from the lambda 1.00 ratio and, accordingly, how much the fuel supply needs to be adjusted, which allows the ECU to change the amount of fuel injected and obtain a lambda ratio of 1.00 almost instantly.
Air-fuel ratio sensors (cylindrical and flat) were first developed by DENSO to ensure vehicles meet stringent emission standards. These sensors are more sensitive and efficient than zirconia sensors. Air-fuel ratio sensors provide a linear electronic signal of the exact ratio of air and fuel in the mixture. Based on the value of the received signal, the ECU analyzes the deviation of the air-fuel ratio from stoichiometric (that is, Lambda 1) and corrects the fuel injection. This allows the ECU to accurately adjust the amount of injected fuel, instantly reaching and maintaining the stoichiometric ratio of air and fuel in the mixture. Systems using air-fuel ratio sensors minimize the possibility of insufficient or excess fuel supply, which leads to a reduction in harmful emissions into the atmosphere, lower fuel consumption, and better vehicle controllability.
Titanium sensors in many ways similar to zirconia sensors, but titanium sensors do not require atmospheric air to operate. Thus, titanium sensors are the optimal solution for vehicles that need to cross deep fords, such as four-wheel drive SUVs, since titanium sensors are able to work when immersed in water. Another difference between titanium sensors and others is the signal they transmit, which depends on the electrical resistance of the titanium element, and not on voltage or current. Given these features, titanium sensors can only be replaced by similar ones and other types of lambda probes cannot be used.
Q: What is the difference between special and universal sensors?
O: These sensors have different installation methods. Special sensors already have a connector in the kit and are ready for installation. Universal sensors may not be equipped with a connector, so you need to use the connector of the old sensor.
Q: What happens if the oxygen sensor fails?
O: If the oxygen sensor fails, the ECU will not receive a signal about the ratio of fuel and air in the mixture, so it will set the amount of fuel to be supplied arbitrarily. This can lead to less efficient use of fuel and, as a result, an increase in fuel consumption. This can also cause a decrease in catalyst efficiency and an increase in emissions toxicity.
Q: How often should the oxygen sensor be changed?
O: DENSO recommends that the sensor be replaced according to the vehicle manufacturer's instructions. However, the performance of the oxygen sensor should be checked every time the vehicle is serviced. For engines with a long service life or with signs of increased oil consumption, the intervals between sensor replacements should be shortened.
Range of oxygen sensors
412 part numbers cover 5394 applications, which corresponds to 68% of the European vehicle fleet.
Oxygen sensors with and without heating (switchable type), air-fuel ratio sensors (linear type), lean mixture sensors and titanium sensors; two types: universal and special.
Regulating sensors (installed before the catalyst) and diagnostic (installed after the catalyst).
Laser welding and multi-stage control ensure that all features are exactly matched to original equipment specifications, ensuring performance and long-term reliability.
DENSO solved the problem of fuel quality!
Are you aware that poor quality or contaminated fuel can shorten the life and degrade the performance of an oxygen sensor? Fuel can be contaminated with engine oil additives, gasoline additives, sealant on engine parts, and oil deposits after desulfurization. When heated above 700 °C, contaminated fuel emits vapors harmful to the sensor. They interfere with sensor performance by forming deposits or destroying sensor electrodes, which is a common cause of sensor failure. DENSO offers a solution to this problem: the ceramic element of DENSO sensors is coated with a unique protective layer of aluminum oxide, which protects the sensor from poor quality fuel, extending its life and maintaining its performance at the required level.
Additional Information
For more information on the DENSO oxygen sensor range, see oxygen sensors, TecDoc, or your DENSO representative.
