Firstly, I have to confess that I'm not a diesel expert! I'm an electrician with basic knowledge of common rail diesel injection systems.

This vehicle has an intermittent starting fault. No codes recorded. Feul pressure is constant at around 350 bar when cranking, I have also scoped the pressure sensor under cranking to check for voltage drop out etc. It will generally always fire briefly and then carry on cranking, It does however stop pulsing the injectors.

I've checked cam and crank signals back to the ECU. It always shows an RPM reading when cranking and battery voltage is well up.

I have done a basic injector leak off test but only using 10ml glass tubes in my Sealey Kit. After about 10 seconds, injectors 1 and 4 have filled the tubes whilst 2 and 3 are only half full. This does appear to be a little suspect but it wouldn't explain why the ECU stops pulsing the injectors when the pressure its seeing in the fuel rail doesn't drop.

Stumped now!