fresh tune up, now having issues starting

ok so this is my girls truck and she is the ony one working on it, im just allowed to show and point. well we did a complete tune up on it the other day, (26th i believe) and today it has been having issues. we first noticed cause the mpg went down. so checked the wires and 2 werent all the way on on the cap. everything else is fine. later on it starts having trouble starting. fine a plug wire on the plug isnt all the way on ( yes i checked these earlier) pop it all the on, and fires up. later again doesnt want to start, so i twist the wires a little and it fires up. she left to leave for work, wont start AGAIN. so i check them all again, and starts, moves a bit dies, and wont start again!

could the brand new plug wires be bad, or am i bumping something else with out realizing it?

Check the coil tower for burn out. It could be shorting out.

I'm actually just getting ready t check the coil

Some one replaced the coil, and never tightened the nuts down that child then wires to the coil. I think that was the problem