A while back I had an 89 trans am L98 car that I was super familiar with mechanically, however it was unfortunately destroyed in a fire. About a month ago I picked up an 87 trans am with a carbed 305 and a 5 speed. When I went to look at it at the sellers house we ran it for a while and drove it around the block, and when I shut it off there was a humming sound coming from under the hood that almost sounds like an electric cooling fan. When I asked him about it he said something about how it's smog equipment that blows air into the carburetor, and since I'm not super familiar with the LG4 I believed him. Well I've dug around under the hood a little more as well as looked online and have found no info on what this thing could be. There is some sort of pump or fan inside of the passenger side fender right next to where the battery sits, and there's tubing that runs from it all the way next to the carburetor and clips next to the fuel inlet line where it seems to just dump right out instead of connecting to the air cleaner or to some sort of vacuum line. When the pump is running and I stick my finger next to the end of the pipe I can't feel air going in or out. I'll put pictures and a video below but the pump only turns on if the key is off and the car has been running for more than a few minutes and stays on for 5 or 10 minutes after you shut the car off depending on how long it's been running. Is it some sort of aftermarket smog equipment or is it something else?



edit: sorry it wouldn't let me attach a video, something about the wrong file type.

 

It was GM's blower kit to help with fuel issues from fuel vaporization.

This is the kit:
https://www.thirdgen.org/forums/hist...lower-kit.html

 

That makes a lot of sense, but I thought only the L69s had fuel boiling and vapor lock problems? And shouldn't there be more air blowing out of the end of the tube if it's meant to cool the fuel line down?

 

LG4 and L69 both had the same issues

the L69 and later LG4 got the in-tank helper pump that solved most of the issues.

 

I would leave it all in place. A reminder of the 1980s and an era gone by.