Wideband Lambda and Onboard Diagnostic Project
Discussion
I would like to introduce you to my new project in addition to my MBETool. My plan is to replace the unreliable narrow band Lambdas with a wideband version. In addition to that I will make a small diagnosis system with a 4.3" touch screen which can show the Lambda values. I want to integrate this with the MBE ECU to show all the values from the ECU with all the possibilites of my current MBETool.
Here in this thread I will show you the progress of my project and I will for sure collect your ideas, because in the end I would like to give the project to the public.
At the beginning the hardware:
I will use Bosch LSU4.9 Sensors which will replace the original narrow band sensors. Wideband Lambdas are only reliable and accurate with a special controller. I will use a ready made version which is built upon the original Bosch CJ125 Chip. This Controller has a narrow band simulator to connect it to the MBE ECU and a serial interface to get all the values and diagnostic information.
Because of the integrated narrow band output of the Lambda Controller the most important part (Driving the Lambda-Input of the MBE) is independent from the Microcontroller that I will use for the display and the user interface.
The used Microcontroller will be an Arduino Mega 2560:
The Diplay is 4.3" big, has a touch screen and an integrated MicroSD Card Slot which I will use in the future for data logging purposes:
My current plan is to integrate the Lambda Controllers and the Microcontroller together with a power supply in an enclosure which will find it's place in the passenger footwell. This allows me to route the Lambda sensor wiring loom through the battery box the shortest way to the Lambda Controllers.
The Display will find it's place under the dash over the transmission hump.
First I will do a 'rough' version of the software, which will display all the important values from the Lambda Controllers. The next step will involve the connection with the MBE ECU and displaying all the values from the Engine. After that the diagnosis functions will be expanded and things like a Throttle Reset Function will be integrated.
I'm thinking about doing a version without all the wideband lambda things. This would be a portable version of my MBETool.
In this thread I will keep you updated about the progress. But first I have to visit the Burghley Gathering :-) Maybe we will meet us there...
Here in this thread I will show you the progress of my project and I will for sure collect your ideas, because in the end I would like to give the project to the public.
At the beginning the hardware:
I will use Bosch LSU4.9 Sensors which will replace the original narrow band sensors. Wideband Lambdas are only reliable and accurate with a special controller. I will use a ready made version which is built upon the original Bosch CJ125 Chip. This Controller has a narrow band simulator to connect it to the MBE ECU and a serial interface to get all the values and diagnostic information.
Because of the integrated narrow band output of the Lambda Controller the most important part (Driving the Lambda-Input of the MBE) is independent from the Microcontroller that I will use for the display and the user interface.
The used Microcontroller will be an Arduino Mega 2560:
The Diplay is 4.3" big, has a touch screen and an integrated MicroSD Card Slot which I will use in the future for data logging purposes:
My current plan is to integrate the Lambda Controllers and the Microcontroller together with a power supply in an enclosure which will find it's place in the passenger footwell. This allows me to route the Lambda sensor wiring loom through the battery box the shortest way to the Lambda Controllers.
The Display will find it's place under the dash over the transmission hump.
First I will do a 'rough' version of the software, which will display all the important values from the Lambda Controllers. The next step will involve the connection with the MBE ECU and displaying all the values from the Engine. After that the diagnosis functions will be expanded and things like a Throttle Reset Function will be integrated.
I'm thinking about doing a version without all the wideband lambda things. This would be a portable version of my MBETool.
In this thread I will keep you updated about the progress. But first I have to visit the Burghley Gathering :-) Maybe we will meet us there...
The Main Goals are:
- Replacing the inaccurate and unreliable Lambdas with modern accurate and reliable Sensors.
- Displaying the Mixture values while you drive, so you can detect lean mixture which can lead to engine failure.
- Displaying the Engine ECU values while you drive.
- Interrogating ECU faults, resetting the faults, reset of the adaptive mappings or throttle pots without an extra computer.
- Replacing the inaccurate and unreliable Lambdas with modern accurate and reliable Sensors.
- Displaying the Mixture values while you drive, so you can detect lean mixture which can lead to engine failure.
- Displaying the Engine ECU values while you drive.
- Interrogating ECU faults, resetting the faults, reset of the adaptive mappings or throttle pots without an extra computer.
I'll join in the I don't quite understand it, but I'm not 100% certain what Lambda sensors actually do either 
You do however have my admiration for doing something about whatever it is they do badly and for your ECU software, which I've downloaded but not yet used.
I will be no help whatsoever on this project as you may imagine. But good luck anyway.
You do however have my admiration for doing something about whatever it is they do badly and for your ECU software, which I've downloaded but not yet used.
I will be no help whatsoever on this project as you may imagine. But good luck anyway.
Looks like an interesting project. I understand the electronics and software side of it, no idea about Lambda sensors though.
Did you consider the noritake-itron smart tft modules ? We've used them on a few projects, nice and compact with processor you can write code for but probably more expensive than the Arduino route.
Did you consider the noritake-itron smart tft modules ? We've used them on a few projects, nice and compact with processor you can write code for but probably more expensive than the Arduino route.
@Paul: Interesting things, these Noritake Displays. I use the Arduino system because I did a few things with them in the past. I use the Gameduino 2 Display, which has a very good software library.
@All:
Regarding Lambda Control: I try to explain it in short words, but be generous with me, English is not my native language.
For making the correct fuel/air mixture in the engine the ECU relies mainly on tables, which are programmed into the ECU (part of the 'mapping'). For self control every bank of the SpeedSix (Cyl1-3 and Cyl4-6) has a Lambda sensor, which measures the exhaust and can detect a lean (less fuel) or a rich (more fuel) situation. With this measurements the ECU tries to correct the mixture up or down, depending what the Lambda probe says. These correction values are stored in the ECU as the 'adaptive mappings' for future reference.
But there are several short comings:
1. The Lambda probes used in the TVR are only ON/OFF units: They don't really measure the exhaust gases, they only say: It's rich or It's lean. So nobody knows how far you are off.
2. The Lambdas in the TVR are prone to to be very noisy and not very accurate. If they fail it could be that the ECU varifies the mixture in the wrong way.
3. It's very hard for the ECU to detect things which have gone wrong: For example a failed injector, not enough fuel pressure etc.
And there's another important fact: If you press the throttle very fast or the engine is under full load the ECU doesn't use the Lambdas anymore. The MBE then relies only on the mapping tables. So no chance to detect a lean or rich situation under full load.
BTW, A lean Mixture is the worst one. A Rich mixture to a certain amount could be very good.
In simple terms: The theoretical optimal Mixture is around 14,7 air to 1 fuel. This is Lambda 1. If the mixture is more rich, the Lambda value will go under 1. If it's lean, Lambda is greater 1.
Under full acceleration a Lambda down to 0,87 could be good for more power.
Normally all these parameters are programmed into the Engine ECU, either with the original mapping from TVR or a custom mapping from one of the 'guys'.
But as I said, there's no way to detect situations which can lead to an engine failure.
Here comes the Wideband Lambda Sensor: These Probes can measure the real Lambda value of the exhaust fume. They are standard in all cars since a very long time, very reliable and exact.
In this project I use the Sensors only as a monitoring device to check the real mixture of my engine.
One way is to mount these sensors beside the original ones, which involve some working on the exhaust manifold.
Or, the way I will go: Replace the exisiting Probes. This is possible because the Lambda Controller Unit has an output which simulates a narrow band probe. The MBE will work with this simulated signal.
But my Monitor-Display will show the real high resolution Lambda value.
Beside all the Lambda things the second important part of the project is the monitoring of the ECU with all the values and functions you already know from my MBETool. But all these things on a small touch screen where you don't need a computer.
VERY IMPORTANT: My system won't (under normal circumstances) allow you to change anything in the ECU behaviour regarding fuelling. These things are only manageable by the guys wo can do a prober Rolling Road Mapping.
For the advanced: You can change the lean/rich point of the Narrow Band Simulation Signal. So there's the possibilty to change overall mixture to a lean or rich way.
@All:
Regarding Lambda Control: I try to explain it in short words, but be generous with me, English is not my native language.
For making the correct fuel/air mixture in the engine the ECU relies mainly on tables, which are programmed into the ECU (part of the 'mapping'). For self control every bank of the SpeedSix (Cyl1-3 and Cyl4-6) has a Lambda sensor, which measures the exhaust and can detect a lean (less fuel) or a rich (more fuel) situation. With this measurements the ECU tries to correct the mixture up or down, depending what the Lambda probe says. These correction values are stored in the ECU as the 'adaptive mappings' for future reference.
But there are several short comings:
1. The Lambda probes used in the TVR are only ON/OFF units: They don't really measure the exhaust gases, they only say: It's rich or It's lean. So nobody knows how far you are off.
2. The Lambdas in the TVR are prone to to be very noisy and not very accurate. If they fail it could be that the ECU varifies the mixture in the wrong way.
3. It's very hard for the ECU to detect things which have gone wrong: For example a failed injector, not enough fuel pressure etc.
And there's another important fact: If you press the throttle very fast or the engine is under full load the ECU doesn't use the Lambdas anymore. The MBE then relies only on the mapping tables. So no chance to detect a lean or rich situation under full load.
BTW, A lean Mixture is the worst one. A Rich mixture to a certain amount could be very good.
In simple terms: The theoretical optimal Mixture is around 14,7 air to 1 fuel. This is Lambda 1. If the mixture is more rich, the Lambda value will go under 1. If it's lean, Lambda is greater 1.
Under full acceleration a Lambda down to 0,87 could be good for more power.
Normally all these parameters are programmed into the Engine ECU, either with the original mapping from TVR or a custom mapping from one of the 'guys'.
But as I said, there's no way to detect situations which can lead to an engine failure.
Here comes the Wideband Lambda Sensor: These Probes can measure the real Lambda value of the exhaust fume. They are standard in all cars since a very long time, very reliable and exact.
In this project I use the Sensors only as a monitoring device to check the real mixture of my engine.
One way is to mount these sensors beside the original ones, which involve some working on the exhaust manifold.
Or, the way I will go: Replace the exisiting Probes. This is possible because the Lambda Controller Unit has an output which simulates a narrow band probe. The MBE will work with this simulated signal.
But my Monitor-Display will show the real high resolution Lambda value.
Beside all the Lambda things the second important part of the project is the monitoring of the ECU with all the values and functions you already know from my MBETool. But all these things on a small touch screen where you don't need a computer.
VERY IMPORTANT: My system won't (under normal circumstances) allow you to change anything in the ECU behaviour regarding fuelling. These things are only manageable by the guys wo can do a prober Rolling Road Mapping.
For the advanced: You can change the lean/rich point of the Narrow Band Simulation Signal. So there's the possibilty to change overall mixture to a lean or rich way.
Awesome work Evoolli.
Do you plan to market this as a product, or release a howto (for wiring the board up etc). I'm keen either way, can see myself having a couple of 'hobby' weekends building it
Would be fun to see it become the 'pod', wire in the milometer signal etc. Or is that a silly idea?
Cheers
S
Do you plan to market this as a product, or release a howto (for wiring the board up etc). I'm keen either way, can see myself having a couple of 'hobby' weekends building it
Would be fun to see it become the 'pod', wire in the milometer signal etc. Or is that a silly idea?
Cheers
S
donski58 said:
Hi Oliver
Now that you have your engine running well and producing good power why don't you opt for a more modern ECU that can offer you all of the extras that you are experimenting with?
Don
Hi Don,Now that you have your engine running well and producing good power why don't you opt for a more modern ECU that can offer you all of the extras that you are experimenting with?
Don
This was my idea in the first time, but I couldn't find a solution that suited me. And I would like to stay as original as possible...so the decision for a very good mapping and making a diagnostic System for the MBE, which is more fun for me then to buy a ready made version, where nobody gives me the detailed technical details.
Ok, i'm missing knock control, but as I heard from several people you can't be sure that it really works on the SpeedSix.
So, Hardware and Software is ready to go into the car. To show you the progress, I have made some pictures and a short movie:
Here you can see the main part, both Lambda Controllers, the Arduino, some Converters and Power Supply:
For the Display and Touchscreen I have modified an plastic enclosure. It has a 3 foot long cable to mount it under the dash of the Sag. The Main Controller will go into the passenger compartment.
The Software allows monitoring of the Wideband Lambdas together with all the values from the MBE ECU. At the moment there's a main screen with the most important values, a second screen which shows both Lambda Values in big gauges, then there's a third screen which is organized like my MBETool. The fourth Screen shows Current and Logged Faults.
There's the possibility to Log all values onto the MicroSD Card into spreadsheet compatible CSV Files (like my MBETool). You can do some functions on the MBE like resetting the throttle or the adaptive mappings.
The setup screen allows you to set the brightness, rotate the screen, set the default page which is shown on startup.
You can Dim the screen in the night or switch the screen off...with a touch it's on again.
This is the current state. I have some more ideas like a scope screen, but first I will mount it into my car and see how it works in reality.
In the small (unprofessional made) Youtube video you can see the possibilities:
http://youtu.be/KGqeagr3bXU
Here you can see the main part, both Lambda Controllers, the Arduino, some Converters and Power Supply:
For the Display and Touchscreen I have modified an plastic enclosure. It has a 3 foot long cable to mount it under the dash of the Sag. The Main Controller will go into the passenger compartment.
The Software allows monitoring of the Wideband Lambdas together with all the values from the MBE ECU. At the moment there's a main screen with the most important values, a second screen which shows both Lambda Values in big gauges, then there's a third screen which is organized like my MBETool. The fourth Screen shows Current and Logged Faults.
There's the possibility to Log all values onto the MicroSD Card into spreadsheet compatible CSV Files (like my MBETool). You can do some functions on the MBE like resetting the throttle or the adaptive mappings.
The setup screen allows you to set the brightness, rotate the screen, set the default page which is shown on startup.
You can Dim the screen in the night or switch the screen off...with a touch it's on again.
This is the current state. I have some more ideas like a scope screen, but first I will mount it into my car and see how it works in reality.
In the small (unprofessional made) Youtube video you can see the possibilities:
http://youtu.be/KGqeagr3bXU
glow worm said:
It's a lot easier to go for the new MBE ECU with wideband Lambdas and anti-knock sensor , more expensive but since the original MBE ECU is obsolete would seem to be more future proof IMHO .
You are right, but:- Nobody sells you the new MBE in an open state, you buy a locked one....so not for me.
- Making something by our own is much more satisfying than buying things ready made.
The "old" MBE-ECU drives the engine without problems, the only thing I was missing was a control system which show me when something has gone wrong.
Gassing Station | Tamora, T350 & Sagaris | Top of Page | What's New | My Stuff