An engine needs a few things to get going, air, fuel, spark, compression and then timing. If you are for SURE getting all these things in the proper order the engine should run. Start narrowing things down one by one. Trouble shoot before you buy anymore new parts. Make sure that the plugs are firing for each cylinder. If you are not getting strong consistant spark the coil/ignitor could be toast. Do you have a check engine light? If so, pull the code and that can point you in the right direction.