Ok so i've had my Mazda protege now for awhile, bought it used a few months ago. everything worked great until it started stalling. I thought installing a bunch of new things would fix the issue. I've installed new spark plugs, new timing belt , new mass air flow. It'll start but then it stalls on any sort of incline in the road.

Any ideas? Im totally stuck...

Thanks so much!

Its a 1999 not a 1991. So sorry

 

Nothing specific, but a few things you might look in to?
1) Fuel filter
2) Fuel pick up "sock"
3) Fuel pump(?)
4) Vacuum leaks
5) Evaporative fuel recovery system problems, including any leaks. And BTW: DO NOT over fill the fuel tank. Stop on the first or second click at the pump to be on the safe side.
6) If the car seems to bog down, has suddenly developed bad mpg's and/or the temperature gauge goes up when under a load, possibly a clogged cat or bad O2 sensor too.