SCFactory

iTrader: (2)

What is this tube for, it routes behind the engine to the IAC valve position.. its attach to stock 1JZ-GTE twins.. Thank for any input

1997Soarer

iTrader: (1)

Filtered air tube for the IAC. IAC controls engine idle.

Sometimes people block this off and put a small filter directly on the IAC valve

Vrank

iTrader: (4)

^ correct, iscv vent tube is 3/4", k&n sells one for relatively cheap. On MAF cars such as 1j/2jzgte vvti, this must stay routed in this manner unless converting to speed density engine management

SCFactory

iTrader: (2)

Hmm ok but what does blocking it off do? Its just taking vaccum from the turbo side correct? and in what way does it effect the IAC

1997Soarer

iTrader: (1)

This tube feeds air to the IAC. It grabs air from before the turbos. On MAP equipped GTE engines people block this off just to clean up the bay (that's where the filter on the IAC valve comes into play).

What Vrank says is also true. On MAF cars you have to keep this hose or your car will have problems idling correctly.

SCFactory

iTrader: (2)

Thanks, so under a single turbo setup where the intake tube is gone people just put filter, as the rpm rises in the engine the IAC shuts correct? Also is their a proper way to clean the IAC on the 1JZ engines I didn't see any way of removing the IAC from the that metal coolant housing.

1997Soarer

iTrader: (1)

On a single turbo setup, putting the filter directly on the IAC only works if you are deleting the MAF (or your engine is already MAP based).

Sorry, I'm not quite sure what the proper way to clean it would be. I don't think the metal coolant housing is removable. So you would need to take the whole valve off (including the coolant lines) to clean it