Hi Guys

I have searched all the forums for an answer to this but still none the wiser.
My car intermittently refuses to start after being driven perfectly normally for loads of miles.Leave it for a few days and then bingo it will strt and run again till you turn it off.
At no time do you get any fault codes on a machine and there is no evidence of any problem other than no start.
Here is some info.When trying to start it it in its fault condition and depending on how long you have left it it sometimes appears to have normal compression and runs for ten secs or so before dying.Then if you try again it appears to have no compression and spins over fast.Testing the compression shows 30lbs max.If left for a while it may get some compression back and attemp to fire intermittently for a bit before entering its no compression mode once again.

Changed cam sensor but no change.Cleaned throttle body and checked on machine seems ok.Unplugged cam sensor and machine shows cam sensor unplugged[unsurprisingly]All the time it appears to have no compression it does not fire.Sparks are ok.Fuel is ok.
Here is the theory but not sure if anyone else has any experience.
What if the cam adjuster mounted on the inlet camshaft had jammed or the valve feeding oil to it had a bad seal which allowed oill to advance the cam.
Would it be sufficient to cause no compression,Would it be the mechanical rotor assembly itself or the valve controlling it.
Unplugged the valve and attempted to start it and no difference.
Then out of the blue it started and i unplugged the sensor/valve whiile it was running and tried to start it again.|It started.Left for a while and attempted again and it ran for the 10 secs and died again with no compression.

Does anyone have any ideas about this?

Any thoughts most welcome.
Thanks in advance

As i say have looked everywhere but seems no info.