I guess we'll start with some basics
When you have the start problem does it turn over at all or is there nothing?
Auto? Manual?
When you crank it does it sound normal? Does it sound like it wants to fire?
Put a paperclip between FP and B+ then turn your ignition to the ON position. Go and listen to your engine, do you hear the fuel running through the engine? Also listen to your tank, can you hear the pump (stockies are usually rather quiet) Does it sound ok or does it make strange whine noises?
Have you got spark? Pull out lead #1 and stick a plug in it and see if it fires.
How are the wires in your cps? These are common to cause a cranking no fire problem.
Let me know the answers to the above and we'll go from there