I've just completed putting my engine back in. All wired up but will not fire. I have spark but still no fire. Could this be a sensor or I have done the timing wrong or fuel. It's my first fuel injection rebuild

 

Its hard to say what the problem is. What did you do to the engine exactly? Is it all the the same parts fitted as when it was last running? Obviously you need spark, fuel, compression and correct timing etc

 

I completely strip back to block redone head gaskets and assembled back. I marked the time belts and cams and line it all back up to the exact markings. I guess I should of gone top dead center and done the timing from there

 

are the fuel lines on the right way??

 

Is the fuel pump priming? Do you have fuel at fuel filter? Its possible you have injector plugs on wrong . i.e. Front plugs on rear injectors and vice versa