Wont start

One day while driving, car started sputtering and died, got it started but service now light was on. So I had it towed home, and couldnt get it started, while cranking, it blows white smoke from the TBI and if I turn off the key before it dies, it will backfire. It will sometimes start, but die as soon as I give it any throttle. Then one day I tried, popped right off and ran fine, so I changed fuel filter and it ran great, drove it for about 3o miles, then sputtered and died like before, so I changed the fuel pump and still no luck. Has spark and but I never checked the plugs. Its getting fuel to the TBI so im lost as to what it might be, any ideas?