93 notchback of mine is having difficulty starting and holding an idle without sputtering/back firing and dying. Also back fires and sputters when any load is applied proceeded first by a hesitation. Ive checked my fuel filter. Fuel pump. Distrubutor and timing. I have a clean MAF. Throttle position sensor is correct. Im completely stumped. Anyone know wtf is going on?

 

Kinda sounds like how my stang was awhile ago. I'd check all gaskets, and fuel injectors

 

Check all of your vacuum lines too. I ran into that problem a while back.

 

Check your map sensor

 

Could be a timing issue or perhaps the timing chain jumped...

 

+1 and check for vacuum leaks in general in the intake manifold vacuum fittings and the area it attaches to the heads and where the upper & lower portions join for good measure. Especially if those have been removed or replaced recently.