Quote Originally Posted by The Alchemist View Post
So in my case, the o2's were working from very cold at the factory temp setting B1502/04 is -40 and the runtime 10secs, once I see STFT activity these tables do sweet nothing! I will raise the temp settings to 60degC as you have suggested.
mmmmm
SOooooooo why was the commanded 14.68 yet the measured AFR was slightly lean at 15.2 when I was free revving at 2000rpm (was measuring at the tail pipe with reversion) then at 14:16.33 in my log the STFT suddenly changed from +10s to -3's when the ECT crossed over 80degC and the actual AFR changed to? What suddenly changes at 80degC to cause this?
AND when you reach 60degC and the STFT's are working is there no ECT enrichment table as such to adjust, its all just done by the VVT and STFT's???

BTW that idle stuff was awesume thanks got this car idling with zero swing sounding almost stock lolol !!!!! Couldn't believe the difference!
Set them to 60 degrees C, the stft changes rapidly by the sounds of it, I will look at the log tonight, But the open loop tables are the only tables that have an effect on commanded afr, the engine will want more fuel cold aswell. Once the ects are hot and oil temps right up the IVT should be around 160 degrees and afrs will stabilise at this time IATs will have increased aswell from heatsoak in the manifold/blower. Also commanded idle rpm and TP%, idle vacuum changes can all alter afr suddenly if it drops to a different cell in the vve. Especially with the vve where individual cells cannot be changed so easily without affecting other areas. The IVT table multiplier changes commanded afr, If the afr changes by 13% and the commanded afr is still 14.68:1 it is most likely IAT and vve related, open loop alterations will show a difference in commanded afr.

I'm glad the idle instructions worked out for you, The e38 really eats the early pcm for controlling big cams once you get the hang of it. Once you nail min idle air,(which is basically desired airflow) you can raise max idle air back to factory values. min idle air is very sensitive and the easiest way to get it right is how I outlined it, by getting max idle area to the correct value, then lowering min idle air gradually until you can see the throttle blade trimming slightly when the throttle closes. 1 g/s to far and the trimming will be overactive and overcompensating, in which the first thing people do is start to make proportion and integral correction less aggressive, which does not need to happen. If you sneak up on min idle air by dropping it gradually you can get it spot on and the trims will only move plus or - 0.4%. Say if its idling at 18.0% it may go 17.6% on decel and recover idle with 18.4% before settling to 18.0% with 100% stock proportion and integral values. In which case I am very happy with as only the critical tables are altered. Once this outcome is reached see how the car feels to drive and work on getting coast down timing and idle timing correction right. After a bit of driving the idle gets even better as you may of noticed the e38 can really trim nicely and accurately if min idle air is right. The next morning I add 0.08 to max idle air and make sure I have enoguh air cold. If the engine is lagging behind commanded rpm and timing is high I basically keep bumping max idle air until the idle timing is around 15 degrees. I have found they cold start and drive cold a lot better by using more air rather then timing to get them starting and driving smoothly. I also suggest zeroing out cold noise reduction timing. This creates a lot of problems with a cammed car. The factory os adds timing cold in ect correction and then removes it in cold noise reduction? I just zero out both and run same timing cold to hot, I found it is the easiest way to do it.