Hello I have a Vauxhall astra h 1.7 cdti won't draw fuel from tank I have changed tank unit / fuel rail sensor/ and fuel pressure valve on high pressure pump checked fuses and relay . still no start turns over good thanks .dave

Have you checked the crankshaft sensor as the fuel system needs to see a signal that the engine is rotating before fuel is delivered.
Also, ensure that the fuel inertia cutoff switch is not off - reset the switch to ensure it is on and the fuel pump can then operate

No but I will check it out thanks . where is the shut off reset switch please thanks .dave

Hi Dave, using the power of google, I have found that the cut off switch is located under the instrument panel to the right of the transmission hump. If it is not , then it can either be behind , or below the glovebox, or behind the side panel next to the drivers door. 

Hope this helps. 

Regards Andy.