When my car sits for a while (4hrs or so) it takes a few cranks of the key to start up.

This happened the day I took the rocker cover off, also the day before it got an injector and fuel rail carbon clean/flush.

Now I'm thinking a leaking injector but one of the bolts on the fuel rail is stripped so I want to see if it could be anything else before I have to remove a stripped bolt.

Anyone have any ideas?

Or any tips on how to remove a stripped bolt.