Immobiliser

[C2K]

Ok well the first, and free thing to do, is to back-track your steps. Provided that the crank is correctly plugged in and the speed sensor too you're pretty much done down the back.

Remove all the gubbins around the battery and examine what you've been fiddling with to ensure that a) you've put everything back and b) it's all tight. It doesn't cost anything to do except a bit of time and you may find you had a brain fart during re-assembly, or as i've had before - you've trusted a mate to do a job and they didn't.

I think you need to get something like PCMScan and attempt to monitor the rail pressure, to establish that your LP pump s pressuring the rail correctly as iirc it needs like 120 bar to start, which your pump may be failing to deliver, or may accidentally be bypassing and returning due to lack of signal or poor signal from the pressure sensor or malfunctioning of the regulator etc.

Thinking out loud really. Oh, and cam sensor is on the left hand side of the head near the filler cap, reading the cam pulley.