This is a long read. You might consider to skip to just after the video.
Yesterday I changed my MAF for a unknown one and while this old MAF checked out to be best with Datascan (a simple voltage check with no running engine), I couldn't imagine it would help. From the other MAF's I selected the one with the next lowest voltage and the difference in voltage is very, very small.
But gues what, while I'm not fully sure because the stalling is intermittent and only with cold starts, this looked like it went away at times but it didn't and now with this other MAF the A/F base is 100, the lambda only goes lean when I rev te engine and the stalling is not back yet. Also the darting went from almost impossible to evade by clever pedalling and clutching to very, very annoying so I was a bit dissapointed and that is an understatement.
Today I got around to swap the fuel rail from rust-egg to my Nx. I'm not sure why I was a bit reluctant to this, it ain't hard and I did the spray test you mentioned Ben. I couldn't imagine my problem would be solved and it isn't but it went to the background for about 50 to 60 percent. This fuel rail from rust-egg has a fpr screw that had been molested before and this rail I will take to my work to see if with some help and some cleverness I hope a collegue comes up with, to make it loose. Or else I will drill that little bastard.
For the injectors, sure both rails have 370 cc injectors but they are not the same by colour and those four little holes also don't look the same to me. So I decided to stick with all the injectors which I believe is a good idea since those have the same history. I'm not sure if I'll be able to find out which fpr is best by trial and error but I will investigate this. I also learned that viewing youtube movies from car mechanics can be very helpful and that if you click on something that takes long just skip it or click something else, no time to waste.
I've noticed that for A/F base there is very little to read on the internet and that my old MAF that I still think made my engine stall, showed A/F base varying from 95 to 105 and this MAF is at 100 somehow but my car is smoking bad with this MAF so it mitigated my stalling and time will tell if I'm correct but it is worn also. Still two MAF's to go. The MAF on rust-egg has a little part number difference and if memory serves well a MAF from a non lambda lowport SR20 and a MAF from a lowport SR20 with lambda have three and four wires or the other way around. I will need to check this because rust-egg isn't darty.
So I'm a little optimistic since the darting became worse by another MAF but went to the background by swapping a whole fuel rail. I ohm tested the injectors and they are between 11.5 and 12.5 ohms. I also spray pattern tested the suspected fuel rail and while I never saw this before, all four where the same. On the other hand those injectors seem not to be really defective but the darting shows somewhere between 1000 and 1500 rpm and I can't tell if a spray pattern test should show something or not.
For the MAF by the way, now I can hear the humming sound of the front tyres and those are Pirelli's. But if Pirelli calls something 'Cinturato' I read crap tyre. But those tyres are good second hands so I couldn't be picky but I would not recommend them since I believe a B brand tyre will perform similar or better. However, back again to the drawing board, asking a question on Meta Mechanics Stack exchange or how they call it, gives fast replies by knowledgable people but it are generic answers, finding someone who has specific SR20 knowledge is hard overthere.
I'm not sure if being stuck in open loop went away but testing that is better to do with a home to work drive and for the dartyness it is still there and I believe is something else, but the engine hangs up too quickly at times with throttle closed and there is not much left to test.
The only explanation I have almost every if not all sensors and stuff on my engine is and was in bad shape besides aftermarket parts that just don't work well enough, that the French owner fueld it with leaded petrol a few times. I've bought this car with one year of MOT but the catalyzer showed a hole.
https://fotobakje.nl/tmp/VIDEO0121.mp4 (I wan't able to use VIDEO tags successfully)
Here is a movie of the idling, I like it but it isn't how it should be. If someone would speculate what is wrong I really would like to hear!
So the darting went to the background by fuel rail swapping, the other worn MAF made the stalling go away (I think) and ther is not much left to check.
I will do some homework and rewrite my initial question!