Adaptives at -30%
Discussion
Yesterday i had my MOT, prior to it I decided to check that the throttles were balanced and it was running as good as it could.
I connected the laptop up and noticed the adaptives were -25% and -29%, no faults showing, I balanced the throttles up and they were alittle out, not by much, when done I reset the throttle position and then the adaptives. Car now runs smoothly and just passed its emissions test although the lambda was high. When I got back I decided to check the adaptive again and its now reading -29% and -30% indicates the throttles are pretty well balanced but why such a high - figure?
I connected the laptop up and noticed the adaptives were -25% and -29%, no faults showing, I balanced the throttles up and they were alittle out, not by much, when done I reset the throttle position and then the adaptives. Car now runs smoothly and just passed its emissions test although the lambda was high. When I got back I decided to check the adaptive again and its now reading -29% and -30% indicates the throttles are pretty well balanced but why such a high - figure?
The readings on the lap top are up and down so much its hard to tell, but it was not at 1 at the test station.
Thinking about it, he said it was rich yet when I looked the lambda was 1.14, wonder if he is getting confused.
I have a wide band o2 and display that i use for tuning honda's, the clamp wont fit up the tvr's ends cans but will have to make something up at see.
Thinking about it, he said it was rich yet when I looked the lambda was 1.14, wonder if he is getting confused.
I have a wide band o2 and display that i use for tuning honda's, the clamp wont fit up the tvr's ends cans but will have to make something up at see.
Edited by BGB autosport on Sunday 27th September 21:04
BGB autosport said:
Thinking about it, he said it was rich yet when I looked the lambda was 1.14, wonder if he is getting confused.
That does seem confusing. I assume that -30% adaptives means the ECU has reduced fuel by 30% i.e. the ECU thinks it's running rich. If your independent tester also said it was rich that would make some sense.
But contradicting that the high lambda would indicate that it's running lean and prompt the ECU to add fuel not remove it. All very strange.
If it really is running rich (despite the -ve adaptives) it might indicate the fuel pressure is too high so worth checking that if you have the equipment available.
In an ideal world the adaptives should be 0% but due to engine difference and the fact that from the factory one map is used, the adaptives alter to suit the specific engine. The adaptives are not there for enrichment under acceleration, throttle position or MAP.
If the ecu is remapped to the specific engine then the adaptive should/would be closer to 0%, However stating that the adaptive should be XX% is wrong. They should be within a tolerance + or - of 0%.
If the ecu is remapped to the specific engine then the adaptive should/would be closer to 0%, However stating that the adaptive should be XX% is wrong. They should be within a tolerance + or - of 0%.
You'll never get the adaptive trim map perfect, part of that is because of the way the targetting is set up which means it can be some way off the centre of a cell and still start learning a trim, it's one way of getting a quick learn on the adaptive table : by making it learn values which aren't strictly speaking correct.
However there are certain fixed values and one of those is the throttle position signal output at idle, this is because you can reset that in the software when you're tweaking the airflows around .. basically every time you touch an air screw adjustment you should always reset the throttle pots before deciding if you've got it right or not. On that basis then the ecu will always look at one point on the load part of the fuel map for whatever revs you are doing .. so .. (crikey) what this means is that (unless you have some other fault affecting the results) a value of -30% means that you have too little airflow for the part of the fuel map being read .. so increase the aiflow on the idle screw and reset the throttle in the software and look what happens ..
It will start to get closer to 0 on the adaptive trim, with hopefully the tickover somewhere around 900-950rpm.
Hope that all makes sense.
However there are certain fixed values and one of those is the throttle position signal output at idle, this is because you can reset that in the software when you're tweaking the airflows around .. basically every time you touch an air screw adjustment you should always reset the throttle pots before deciding if you've got it right or not. On that basis then the ecu will always look at one point on the load part of the fuel map for whatever revs you are doing .. so .. (crikey) what this means is that (unless you have some other fault affecting the results) a value of -30% means that you have too little airflow for the part of the fuel map being read .. so increase the aiflow on the idle screw and reset the throttle in the software and look what happens ..
It will start to get closer to 0 on the adaptive trim, with hopefully the tickover somewhere around 900-950rpm.
Hope that all makes sense.
spitfire4v8 said:
You'll never get the adaptive trim map perfect, part of that is because of the way the targetting is set up which means it can be some way off the centre of a cell and still start learning a trim, it's one way of getting a quick learn on the adaptive table : by making it learn values which aren't strictly speaking correct.
However there are certain fixed values and one of those is the throttle position signal output at idle, this is because you can reset that in the software when you're tweaking the airflows around .. basically every time you touch an air screw adjustment you should always reset the throttle pots before deciding if you've got it right or not. On that basis then the ecu will always look at one point on the load part of the fuel map for whatever revs you are doing .. so .. (crikey) what this means is that (unless you have some other fault affecting the results) a value of -30% means that you have too little airflow for the part of the fuel map being read .. so increase the aiflow on the idle screw and reset the throttle in the software and look what happens ..
It will start to get closer to 0 on the adaptive trim, with hopefully the tickover somewhere around 900-950rpm.
Hope that all makes sense.
Makes perfect sense and luckily that’s exactly how I did it, and your post confirms that there may be a problem somewhere else, just a case of tracking it down. However there are certain fixed values and one of those is the throttle position signal output at idle, this is because you can reset that in the software when you're tweaking the airflows around .. basically every time you touch an air screw adjustment you should always reset the throttle pots before deciding if you've got it right or not. On that basis then the ecu will always look at one point on the load part of the fuel map for whatever revs you are doing .. so .. (crikey) what this means is that (unless you have some other fault affecting the results) a value of -30% means that you have too little airflow for the part of the fuel map being read .. so increase the aiflow on the idle screw and reset the throttle in the software and look what happens ..
It will start to get closer to 0 on the adaptive trim, with hopefully the tickover somewhere around 900-950rpm.
Hope that all makes sense.
Since balancing the throttles the engine is starting and running smoother and better than it ever has since I have owned it.
I was planning on welding an O2 bung into each of the manifolds over the winter so I can use my wideband sensor it check the exact fuelling. Looks like I may be doing this a little sooner to see exactly whats going on.
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