So yesterday, I used this application and scantool called autotap on my car. I got a display of everything supported by my car and found out my ignition timing advance is off by -20 degrees. Could this be the reason why it won't start?

 

yes, this is enough to cause trouble.

I helped BengalBrad to get his MX 3 started again. First make sure your timing belt is set correctly. Use some white paint to enhance the ignition timing marks both on the harmonic balancer and on the timing cover. Then loosen the distributor bolts so you can turn the distributor by hand and turn it counter clock wise, facing the distributor cap. Now get a helper to crank the engine while you turn the distributor clockwise until the engine starts and keeps running. Now use a timing light to set the ignition timing. Check it once more when the engine is properly warmed up.

Let us know how it goes.