91 Sunbird will turn over but not start

I was giving it a tune up and replaced the spark plugs and wires(correct to the car, and gaped right) roter button and distributer cap, and gave it an oil change. I even did this all with a mechanic standing right behind me makeing sure I did everything right. Once I got done I tryed to start it and it tryed to start but wouldent. We cheaked to make sure it was getting gas and spark (by grounding out the spark plug to the engine block) it gets everything it needs to start, but just wont actuially start. We have asked like 15 mechanics whats wrong and theyve pretty much all told us "we have no clue". Could u weigh in on whats wrong?

p.S. We had 1 mechanic tell us to change the egnition module (the module hooked to the distributer) but we havent tryed that cause he said it was just a "test" and he wasnt sure if it would actuially do anything.