2002 Cavalier LS won't start

[dc10nc]

As the thread title says, its a 2002 Cavalier LS Coupe 5 Speed. 2.2L SFI, 98,000 miles.

The car was sitting since the middle of December 2010, was turned on once or twice through out that time, no problems what so ever. So I go to lend it to my friend since I can't drive it, and having it being driven around is better than it just sitting there go to waste. Anyway, he comes over yesterday (Tuesday, May 10th, 2011) to clean it out and grab the title from me, we go to start and it starts up perfectly, on the first try, with no problems whatsoever. We let it run for about 5 minutes and shut it off.

He leaves for about 45 minutes to go to the DMV to get it registered, comes back, goes to start it, and nothing. The battery was tested, and its perfectly fine. So we bump started it and it kicks over and runs fine.

The starter on it was the starter from the factory, so we changed it and it still won't start. Also tried to bypass the clutch switch, no luck either. When we turn the key forward we can hear the fuel pump engage, so we know for a fact its getting fuel (still bump starts perfectly fine).

I did this as a favor to my friend, and I'd hate for him to dump another $500 dollars in different parts just so we can get this beast started, seeing as I'll be getting it back from him at the beginning of next year.

Anyone experienced this before, know how to pinpoint the exact problem, or have any general suggestions? Thanks in advance for any help.