Quote:
Originally Posted by Dan03mach
How is the desired lambda read, with the o2's correct? So when you go WOT and switches from closed loop to open loop the o2's are no longer being in use and your car is going only by what the MTF is set at. You can have your base fuel set at whatever you desire and once you go into open loop at WOT the table is irrelevant. What you are saying is if you don't go into open loop your A/F ratio is being controled by the base fuel table and controlled by the front o2 sensors and yes that is correct and your computer will make adjustments to the MTF to reach desired lambda. But like I said earlier once you go into open loop it takes the o2's out of the loop and uses only what is programmed in the MTF.
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Doing what you describe is likely completely screwing up your load calculations, amongst other things. Let's presume that for the factory NA calibration your commanded lambda at 5000 RPM and 750 throttle counts (or say a load of 0.899) is 0.879 (12.3 AFR on 14.1 stoich). Now you come along and really want something more like .799 (11.24 AFR on 14.1 stoich). If all you do to drive it to that .799 actual lambda is increase the airflow in the MAF table then you have fictitiously skewed that actual airflow measurement because the ECM is still calculating the pulsewidth based on the original .879 lambda. The actual airflow through the engine hasn't changed. Its the same now as it was originally, you just want to run at a different lambda at those same conditions. Your load will be higher, spark taken from a different point in the BDL table, etc. What you really want to do is change the commanded fuel point. This is done by changing the base fuel table at that point where you desire the change. The fuel needed to deliver that commanded lambda is then calculated based on the original UNCHANGED mass air curve; you're just asking for and receiving a longer pulsewidth from the injector. Load hasn't changed and the airmass entering the engine remains true. Does this make sense?