I replaced my alternator a month ago & I replaced my battery just last week. My car starts & then shuts right off, idk if I'm holding the push start button for too long or if there is another issue with it.

It starts off just fine in the morning but after driving for awhile. I would start it & it would turn off, I'd give it one more & it appears fine. It has 194000 miles & no check engine light

 

If you haven't done it, double check all connections at the battery and alternator and tighten up any loose ones. If they're nice and tight, check for any corrosion on the connectors themselves.

 

How does it idle and drive if it stays running? Does it ever get opened up on a long hill to pull some RPM? And it never ever did this before?

 

It seems to idle & drive just fine. It happens about once a day. My alternator gave out & I replaced it, then my battery couldn't hold a charge & I bought a brand new one. It didn't start doing this until after I replaced the battery. I noticed I need to be driving around for about half the day