Sometimes is runs good other times it cough and sputters in gear

During the times when the engine just cranks and no start, do you recall the fuel pump priming for a few seconds after you first turned the key to start?
If not, can you do that know and let me know if the engine starts or not, and the next time you get a crank and no start, listen if the fuel pump runs for two seconds.
My very first response was going to be a loose electrical connection in a harness or loose/poor ground. If the engine starts and runs fine now, perhaps wiggling some fuel and ignition/computer wire harnesses around listening if the engine stumbles or stalls at idle. If so, see if something is loose.