mrblonde wrote:hi i had another go at checking as Doc says hard to see evo and ivc clearly redid maths and had better results can we have those other waves please and and a wee peek at 1 or 2 cyl.
We did a capture of running compression on 1 and 2. I tried to upload them but have hit a limit on waveform upload size (its a new forum so there are still a few teething troubles). Anyway waveforms from cylinders 1,2 and 3 look identical. In fact the valve timing and compression looks similar across all cylinders.
The most obvious differences are both on cylinder 4 namely, low cranking compression and exhaust part of the running compression waveform at idle. For comparison:
Cylinder 3 (1 and 2 look the same, including valve timing)
Note the oscillations in the pressure and the rise in pressure. Cylinders 1,2 and 3 only get close to 0 psi towards the end of the exhaust stroke. Cylinder 4 gets there much sooner. Perhaps the exhaust valve is not opening fully / bouncing?
Will try to get the other waveforms that have been requested soon.