I've got a 99 dodge Durango 5.2. I did a motor swap about 4 months ago. Had to pull the intake manifold off to get my fat hands to the top tranny bolts. Over torqued it when putting it back on creating a small intake leak. I work a minimum of 72 hrs a week, so I haven't had time to fix it . The check engine light had been on the entire time. But it had been running excellent. Today my check engine light turned off on my way home from work, then I noticed when I let off the throttle my rpms would drop way lower than normal. So got home turned it off and then tried to turn it back on. Won't start unless I'm giving it some throttle. Any ideas? Fuel pump? The intake leak got bigger?

 

Sound like the IAC (back of throttle body) is acting up/dirty or you've got an issue with the battery/battery connections.

 

I didn't think to check the battery cables because it turns over just fine... Just periodically doesn't wanna start without giving it throttle. But I'll check both of those. Thank you