Cranks but does not start

HI,
I have the 1.6 engine and it is the NXT model. My car is not starting. Engine cranks up but not start. Checked plugs and all fuses every thing works fine. Later a mechanic inspected and said that the fuel pump not running and tried to direct the fuel pump motor and it worked fine. Now the fuel pump also works only when the fuse is toggled and direct line is given but car does not start. The ignition key not engaging the fuel pump by itself and subsequently current not supplied to ignition coil. And engine does not start. Fuel pump and ignition coil should work together when key is inserted which does not happen. Please help. Is it the problem with ECU or some electrical line?

I did a through check with the help of electrical engineer I advised him about the reply you gave me and he did a complete check on fuse box and holder by using altimeter and also using a spare wire connected to a bulb and every fuse works fine because the bulb glows on touching every fuse holder. Now he saw some thing strange and told me which even I would like to share with you. One of the relay switches behind the fuse box is not engaging when key is inserted in ignition this relay is meant for fuel pump and engine management this has four pins two big pin and two small pins. First big pin current supply not happening.

Second big pin supply is good and in one of the small pin whose connection is with fuel motor and ACM box is also not working. Mechanic told me it might be issue with some sensor of the car which is not supplying current to ignition coil and even the spark plug wire is not supplying sparks when engine is cranked by key to start. I am so confused at least if I determine which part is a failure I shall purchase that, but no one here is able to identify the part itself. Waiting for your reply.