Does anybody else have this problem?  My '87 Vanagon Syncro sometimes doesn't start.  By that I mean that I'll turn the key, hear the fuel pump being primed, and turn the key to start the engine and nothing.  I have checked the battery and it is fine.  What makes this unusual is that I will come back (sometimes in a few minutes, sometimes in a few days) and it will start right up.  It doesn't seem to be tied to the weather.  

Any ideas?

Thanks,

Pete