I've checked Dme checked many times when I was dealing with a previous issue, definitely all plugged in. I'll have to get around to try and replacing the sensor, I have a spare here. Looks like it will be a tough job with the motor in the car.
A bit of an update, one step forward, two steps back kind of thing.
I swapped injector 3 and 4, no difference, still misfiring on 2 and 4. I decided to put some fresh fuel in (40L) as it turns out my tank was just about empty and putting fuel in got rid of the left fuel level sensor: Short curcuit to B+ error (I thought tank was showing empty becuase of this error on Ista). Anyway, started the car, same thing, cyl 2 and 4 misfires (only on DME counter, not throwing codes).
I reset all adaptations again then let the car idle for a couple of minutes. The counter was no longer showing misfires however it is still running rough at idle speed (idling at 675 RPM), and particuarly approx 850 RPM, engine is visibly shaking and can be felt in the car. If I accelerate to approx 1100 RPM it feels much smoother, then feels like it is missing again higher up (2500-3000ish). Rough running values for all cylinders are between -1 and +1 however jump around at various RPM (see video). After cycling through RPM range for a little bit, I checked misfire counter, and I had a single misfire on cyl 7.
Turn the car off, wait for a bit, then do much of the same. Now cyl 4 is showing misfires again, rough running values for all cylinders at idle back at between 5-10. However at approx 1100-1300RPM, it feels smooth and rough running values are back between -1 and +1. At various points, the misfire counter on 4 will stop, then start again.
I have upload a few videos to youtube in the links below.
https://youtube.com/shorts/O79zOQj9Ou8?feature=share
https://youtube.com/shorts/xIMSAN-1jhI
Quite stumped here
