Faith No More
Saturday, 20 September 1986
L.A. Street Scene
Los Angeles, CA, USA
Pills For Breakfast
The Crab Song
Introduce Yourself
As The Worm Turns
Chinese Arithmetic
We Care A Lot
drums and vocals only
with original album lyrics
with Funkadelic, "Get Off Your Ass And Jam"
Confirmation:
Setlist.fm
Audience recording archive.org (mislabelled)

Bob Baker, Los Angeles Times 19th Sep 1986 lists all bands and stages. FNM at 4pm on stage 16.
LA Times 19th Sep 1986
Los Angeles Times, 19 September 1986, part II, page 3

Possibly same gig referred to in this newsgroup post: Google Groups

Due to the setlist this recording is most likely 1986 (was originally listed as 1987).

LA Weekly, 19-25 September 1986, page 60 - full time table
Description:
There are crowd control issues throughout the gig with the crowd being told to calm down and stop slamming.

The Crab Song is introduced as "this song is called The Crab". During the intro they offer "free t-shirt to the biggest slammer, hey let's start a riot!"
but afterwards they try to calm everyone down, "no slam, just glam"

Chinese Arithmetic has lyrics while just a few months earlier it was instrumental. The introduction includes that mosquito sample as per the album. On the recording someone near the microphone knows the words.

Before We Care A Lot: "oh this is our hit tune, in case you people don't know we're really famous in some parts of this world". The song is just drums as vocals, with the original album lyrics. It's possible their instruments were shut off? During the song the crowd starts chanting "shit, goddamn, get off your ass and jam" from the Funkadelic song.

After the gig the band says they'll be at Powertools, 6th and Parkview late that night. Powertools was a Saturday Night club. Not confirmed if the band played a show though. Powertools closed down around April 1987 at Parkview, further confirming this show must have been before then.
On This Day:
Year Venue State/Country
1987 Faith No More: ?? CANCELLED L.A. Street Scene, Los Angeles CA, USA
1997 Chuck Mosley Theory: Fireside Bowl, Chicago IL, USA
2016 Chuck Mosley: The Parish, Huddersfield England