engine surging

[Bleary]

Lately right after my transmission swap this just happened today, when i am at a stop if im in neutral or any gear with the clutch job, the engine surges from around 1500-2000k just back and forth for a while.
it stops after a few seconds but it is very odd and at the same time this started the shifts from 1-2 and sometimes 2-3 are pretty rough.

[ImBIMMING]

recheck all your vacuum lines

[flyfishvt]

Yup, thats what did it for me. same thing.

[Bleary]

that makes sense now, ive been running it on downtown richmond roads and hitting a ton of bumps on my originial suspension, must of knocked one loose

[Jeffrie]

O2 sensors do this when their on their way out, fouled plugs also do this.