I have a 1994 chevy truck, I was going down the road and it stopped running. Now all it will do is turn over like its going to start, but won't run. Any ideas what it could be? Thanks

While cranking, check for spark. Good strong spark means the ignition is intact.
You'll need to check fuel pressure. If the fuel pump has failed, you'll need to make certain that power is getting to the fuel pump. If power is getting to the fuel pump, but the truck won't start, you'll probably need to replace it. Big job. The tank needs to come out to access the lock-ring that holds the pump and sender into the tank.

While cranking, check for spark. Good strong spark means the ignition is intact.
You'll need to check fuel pressure. If the fuel pump has failed, you'll need to make certain that power is getting to the fuel pump. If power is getting to the fuel pump, but the truck won't start, you'll probably need to replace it. Big job. The tank needs to come out to access the lock-ring that holds the pump and sender into the tank.

My 94 truck quit running the same way,yesturday. I can smell gas when try to start it and I hear the pump humming. What could it be ?

You likely lost spark, which you need to check for. It's common for the Ignition Control Module (ICM) to go bad on older trucks. Easy job to replace. This is the ideal time to also replace the coil packs.

Check your fuel filter on the frame on under the passenger door,there is also a fuel pump fuse under the hood on the fire wall underneath the cover by the a/c unit enclosed in a black cover