The missfire problem has continued even after the 1GT101 Hall sensor was fitted. After some serious scoping of the engine in free running mode (the scope) we found that once in a while some noise was present on the trigger signal. After 15 or so tries to freeze it I gave up and you would have to take my word for it. If the noise profile is of interest I can draw something. The noise is digital in it's nature and strong enough to trigg the ECU.
It seems like this is present on the 5v feed to the sensor as well, and that there is also some similar noise on the 12v feed to the input to the ECU!
We have tried to drive the sensor with a 12v feed directly from the battery and also tried a temp 12v feed to the ECU from the battery. But not at the same time. I have also tried capacitors on the supply near the sensor and it didn't change anything.
I'm unable to help scope the 12v supply in the car any more but it seem to be more then a bit broken.
What I'm wondering about is the advanced digital filter settings, is that something that can be used on a 12-1 triggerwheel with Hall sensor? -Jörgen
The car developed a missfire problem a while back, the 60-2 trigger seemed suspicious as it had some marks on it. The box and connections was checked but showed no signs of a problem and the trigger wheel was replaced by a 12-1 triggerwheel built for a 1GT101 Hall sensor.
This 12-1 triggerhweel did however not solve the problem. The car now sometimes starts but start to missfire after a while, in some cases it start to missfire at once.
The trigger signal was scoped and found to be good, inside the box at the JP2 jumper the signal was a bit weak (2.6v square) because of the VR chip loading it but as expected the behavior didn't change after removing the R56 resistor.
A long time ago the P259 chip was damaged and it was removed for good. The P259 chip is usually damaged by bad ground but none was found at the time, one suspicious ground connection was reported by Simon when I was there yesterday. I fear that other damage could result if the ground is still bad after the P259 chip is removed.
I currently have the box here in the lab and I will try to stimulate it to see if I can recreate the behavior.
The car is running on 1.0.36 firmware and the config and msq is posterd here:
picture of the engine bay: