94 tbird running rough. Help

Yesterday my wife was out shopping,stopped for gas,and made a few more stops before coming home. After the last stop she called saying the car was hard to start and when it did start it was runing very rough. She got it home and I noticed it was missing pretty bad and a strong smell of gas was under the hood and coming from the exhaust. The exhaust was puffing white and smelled of gas.
Today I replaced the plugs and noticed that some looked ok and others looked a little black like carbon not oil. I also replaced the fuel filter since it hasn't been done in a while and looked for any possible other problems.
It is running a little better but still has the puffing exhaust that smell of gas.
Anyone have any good ideas on what to look for?
I figure that if a sensor has gone bad a check engine light should be on and nothing is showing yet.
I have checked the oil and water to see if there is any signs of a blown head gasket and all seems to look normal.

It's a 94 LX with the 4.6 V8 with 113,000 one owner miles. I'm out of ideas for the night so any suggestions are appreciated.

I found the problem and have it fixed now.

What was the solution?

Number 5 injector was shorted out on the inside and staying open flooding the cylinder. Replaced the injector, changed the oil, and all is well again.
With all of the viewers of the thread I'm really suprised no one ever replied with a suggestion of any kind.