getting fire, but hard to crank? could it be?

getting fire to engine, yet hard to crank at onset. When at stop light it wants to quit. Could this be the fuel filter, fuel pump, or a possible timing belt problem? It was running fine until I took it to a shop for front end alignment, could they have disconnected something that makes the fuel get to the engine? HELP ,gotta have work car...Thanksrunaround