Very rough idle, vacuum hose diagram?

[sidquick]

gday all, i just swaped the heads on my 98 vt and now it has a very rough idle, i have to keep on feathering the throttle just to warm it up. still has good compression.
im preaty sure its the sensor on the back of the left head. it has a small diameter soft hose that comes off it and a larger one diameter one which is much shorter. it has a 2 pin oval connecter and a small tapered shaft on the botom with a triangle hole in it. it has DELCO and REMY writen on it, oh and its black.
now... ive connected the soft long hose off the sensor to the small hard hose that runs with the fuel lines, and the short large diameter hose to ... atmosphere.

sorry about my novice, the only experience with efi is megasquirt related. non of this emmision s#it

cheers, sid

[commo tech]

check the hose that goes from the canister purge solenoid (located at the rear of the drivers side head) under the inlet plenum to the throttle body. very common issue