lower throttle body tube-whats it for?

[Skrewdriver]

Does anyone know what the lower left hand side tube (approx 2" long with an L bend in the middle) is for?What does the other end connect connect to?
There is also another peice of small black tubing coming out from near/under the middle injector ,but it doesnt fit into or over the L bend tube to lower left throttle body-although it comes out at the same plcae.
Cant find any reference in the Gregorys as to what they're for and what they connect to.
Anyone out there know???

[HamaTime™]

Vaccum Purge Line? Connects to a plug at the back of the motor.

[Skrewdriver]

The bigger pipe that points to the left is capped off,but the pipe that points down is worrying me (car is duel fuel,and theres 3 tubes that connect to lpg mixer in intake line,2 from front of car,1 from engine somewhere .)maybe thats why 1 is capped off.
dont wanna start the car in case something bad happens.

[wraith]

Take a picture will make it easier. Seem's to me like you may be talking about the PCV hose.