Need help identifying missing vacuum hose

Tuning up a 2006 Tacoma 4.0L after ignoring it for a long time, and noticed two nipples with nothing on them. I suspect they are supposed to be connected together with a hose. Can anyone identify this? Do they need to be connected?

 

The one on the aftermarket intake should be closed or plugged......the Fuel pressure regulator should have a hose to the intake manifold
Fuel regulator vacuum line?
Discussion in '2nd Gen. Tacomas (2005-2015)' started by Bandit, Jun 11, 2020.

 

Thanks. So if the FPR has no vacuum, what effect will that have? My suspicion is that at high throttle I have higher vacuum and the FPR should increase pressure accordingly, and the absence of the hose means I'm not getting the needed pressure at high throttle but I am guessing.

 

Yes those two should be connected as thats how they are in the stock intake config. Autoparts store vaccum hose of the right size (probably 3/16ths) by the foot will do just fine. Grab 3 ft and cut to necessary length.

 

The FPR helps maintain a consistent pressure...

 

The fuel pressure regulators on 2nd gens are referenced to the air filter box which is basically atmosphere, a lower pressure (vacuum) on the reference port reduces fuel pressure, a higher pressure on the reference port increases fuel pressure.
There should be no need to mess with it, just hook it back up to the intake pipe like it is stock.
Some people that are supercharged reference it to manifold pressure to raise fuel pressure under boost but on an NA engine there's no need to do anything with it.