Some times (in the morning) my car has problems starting up. Eventually, I can get it to start, and it runs fine. After I've driven somewhere, it won't start up again (unless it's left standing for 15 min.) If it sits longer for that, it's no problem.

2002 Jetta 133,000 miles 1.8L

Check for fault codes, see what comes up. Have you done the normal maint. items?

Mine does that about once every 4 months.

My VR6 did that a couple years after I got it. Problem was a vacuum leak.