|Obtaining emission level for IVA
Question: I have a 2004 Seiw Westfield with a 1.8 Zetec with original injection and a MBE 967 ECU. The ECU was remapped and the engine has 140bhp, the engine is original, no modification done except the remapping. The car drives fine and the engine really pushes hard. However to pass the car at IVA in Luxembourg I have fit a catalytic converter.
I failed on emissions at IVA, the idle co was at 5.5%, the co at 2000 rpm was 0.5%. Do you think this is due to ECU retuning or can it be another issue? Oxygen sensor? When I check the sensor voltage in Easimap, the voltage is always at 0,2 and 0,3 Volts. It seems that the ECU is not regulating. 5.5% is really high behind the catalytic converter, I put a 200 cell cat on it, this must be enough to reach 0.5% co at idle. I hope you can help me further because I don't know what to do to pass the car at IVA.
Answer: The MBE967 is actually a very old design ECU, although it is a very nice unit to use. It is not ideal for modern emissions but if you need to retune the engine due to the fact that you have fitted a catalytic converter, you are best using the current map you have as a starting point as opposed to any other options. You will then need to have the map fine-tuned on a rolling road to make the engine drive nicely as well as obtaining the required emissions.
The MBE967 should be sufficient to achieve emission levels that were required around the year 2000, so provided your car is not expected to pass levels that are much tighter, you should have no problems. If however your emissions based on current emission levels, then you may need to replace the ECU and wiring harness with a modern MBE ECU and also you may have to detune the camshafts in your engine as well. This is just for your information, you need to discuss with your local IVA office the levels you are required to meet before progressing further.
If you are seeing a fixed voltage coming from the lambda sensor in Easimap, it can only be assumed that either the sensor is not enabled or the ECU is not calibrated to run a lambda sensor or both. The voltage would normally be fluctuating continually and then the ECU would be adjusting the fuel mixture to try and achieve the desired target lambda value. Due to the age of the ECU and potential software variations, it would be extremely difficult to work out why the ECU isn't adjusting.
Even if you came to the UK with the car, it would take me a considerable amount of time to remember how the software functions due to its age and then even when I have worked out how to adjust it, since it is many years since I have regularly used this ECU and only did limited number of cars for emissions with it, it would not be worth the amount of money you would need to pay. Even if you did spend the time and money to get it to pass the emissions, due to the age of the ECU it is now impossible to repair it due to a lack of components.
The only possibility you have got of passing the emissions is to attempt the following; adjust the fuel mixture manually within the map where idle and the higher rpm checks are made so you can get a mixture suitable for passing the emissions. This would need to be done anyway, even with the lambda control working. This is because the lambda control is only even designed to make small trimming adjustments to ensure that the mixture that is set has small adjustments to reach its target. Lambda control cannot fix a mixture that is nowhere near.
When you run a 200 cell Cat or in fact any Cat, it has to be kept at a very high temperature to function correctly. Normally in a Westfield type of car, the catalyst is a long way from the engine due to the exhaust manifold length, so before attempting an emissions test quite often the car will have to be driven quite hard immediately before the test is carried out and if left too long the temperature of the Cat will cool and fail the emissions.
Setting idle and low speed engine rpm is one of the hardest parts when setting up an engine and when emissions have to be obtained as well, this only makes the job more complex. It is not something normally recommended for the beginner and can only be set up with emissions equipment connected to the exhaust outlet whilst making adjustments.
|Lambda & Auto-tune systems
Question: I have a question for you, can we buy a Lambda sensor and connect it to our MBE system. And does our system contain a auto-tune system?
Answer: As far as lambda systems are concerned, all MBE ECUs of the current spec are able to run closed loop mapping. The MBE9A4 can either run a narrow band lambda sensor, which is only suitable for emissions (Lambda 1) or an external device such as an ETAS, Bosch (professional lambda equipment for calibration) or a system such as an Innovate, which is a club level lambda sensor and controller. Both use a wide band type lambda sensor, which will then transmit a voltage directly to the 9A4. The maps can then be set up in the ECU to allow the ECU to do closed loop adjustments (auto-tune). This facility is available on the high end motorsport MBE ECU, the MBE9A9, which you can directly connect a wide band lambda sensor to.
The only time we use closed loop fuel mapping (Auto-tune) is when we are initially mapping each car/engine. The system is normally disabled after that time and on our high spec ECUs only allow limited changes to occur. This is to prevent damage if the sensor reads incorrectly. Various things could go wrong in competition conditions and if full trust if placed in the sensor reading correctly, this could be disastrous, for example, if a fracture occurs in the exhaust system or part of the exhaust falls off, the sensor could read lean and the ECU could make adjustments based on incorrect information potentially causing engine failure. Also if the sensor reads rich due to the fact that it is beginning to fail or becomes contaminated, the mixture could be leaned off again causing engine failure. So although it is a useful tool, it is only safe when correctly controlled or under mapping conditions, not during a race.