Cylinder 1 not firing on 2007 Mondeo XR5

[C #]

I just replaced the head gasket on my 2007 Mondeo XR5 and am having an issue with Cylinder 1 not firing.

Th engine light is NOT on.

Car idles OK, but if I disconnect and reconnect the coil lead on Cylinder 1 there is no change in performance.

If I disconnect any other coil performance deteriorates and then gets better when it is reconnected (as you wourl expect.

My ODB intermittently tells me that Cylinder 1 is failing with a P301 error code.

If I am driving, it feels like the cylinder is trying to kick in when I accelerate.

We've tested the spark, which looks strong and have swapped coils and sparkplugs with other cylinders.

We listened to each injector using a screwdriver as a stethescope and they all sound the same.

Any suggestions appreciated.

[aussiblue]

How many km has it done? Have you checked the compression on all cylinders?

[C #]

She's done just shy of 200k

Thanks for the tip. We'll check the compression next session

[C #]

The cylinder 1 issue ended up being a valve issue so we had to take the head off again. Fixed that up and now we cant start the engine.
- Timing is right
- We have good sparks
- Engine turns over but just wont start.
It "feels" like the motor isn't turning over as fast as it used to. I'm wondering if it could be starter motor, but an advice appreciated.

[Citroënbender]

What fault codes are you getting?

Will it catch on ether spray but not continue to run?