dont know whats wrong with my car, help... idle issues

[DSM97RS]

driving downtown tonight my car started revving to around 2k rpms when in neutral. i pulled off the freeway and it rose to about 4k rpms while in neutral and at a standstill. it would slowly lower back to 1100, but if i tapped the gas at all it would rise to 4k very quickly then slowly lower again. after i pulled over i turned my car off to see what was wrong and then it wouldnt start again. we pushed it to a space and it started again but would sputter and do the 4k rpm thing again. anyone know whats going on? my car is on 4th st in mpls and id like it back as soon as i can. thanks for the help