Title. I've noticed my car will often idle hunt when coming to a stop when it is in neutral. Seems to only happen when fuel level is less than 1/4 a tank. Fuel pump, sock & filter are all brand new.

Edit: Car is also a JDM model, Series 6.

 

O ring on fuel pump is possible. Not sealing properly, pinched, or something like that allowing air in?

 

What's odd is, there was a plastic o ring looking piece in there that was cracked and the car would hesitate severely at/below 1/4 tank to the point where you could barely maintain highway speeds. I fixed that with a replacement Nipon Denso fuel pump kit, but now when the fuel is low it will sometimes idle hunt. Oddly enough, I drove it tonight to go and get gas, and it didn't hunt at all, even with the fuel being as low as it is. I have no idea what map the car is running, it came with the PFC from Japan, so for all I know it could be a base map, but I have no way to tell.

 

That map will not make a difference with fuel level. I ended up bypassing my whole o-ring set up and went with the hose. I had other issues though.

This issue is cold and hot?

 

I want to say it's when cold and warm.