what i would do mate, is make sure youre getting a spark from the coils, pull the coils out, remove spark plugs, and put them into the coils, and one at a time, turn the engine over and ensure there is a spark, if you are getting a spark, then you can check the fuel supply, remove pipes and turn over engine, you will have petrol running out.
have you tried a compression test ? you need over 100psi to get an engine firing up, this would be a last resort i think, but could be an option, and handy to see what youre engine is doing !
another fault could be the fuel pump, make sure its pumping fuel, either remove it and run petrol through it, or get a pipe to it with some fuel in a can, check all fuses !
thats all i can think of mate,