Yes, push it before you try to start it. You need to experiment to see what your truck likes as far as starting routine. When you push the pedal to the floor and then let up, you are doing two things;
1. You are squirting fuel into the engine.

2. You are relieving the pressure between the throttle and the choke mechanism, so the choke can freely shut and the fast idle cam can set.

You may find your truck starts better if you push the pedal twice before starting, or possible once in the summer, and twice in the winter. The first time will set the choke and give a squirt of fuel and the second time will give another squirt of fuel.