Question about IACV.

I noticed on my truck that after i replaced the IACV that I hear a loud hissing/sucking sound from the throttle body when the truck first starts for a few minutes. Is this normal? I hate not knowing a lot lol.  

i bet that the base idle speed is set too low    or there is carbon on the throttle blades and bore...
on GM tbi units.. you block the idle air bypass passage and set the idle speed with the stop screw to what ever the base idle speed is..   not the normal idle speed...   this is the idle speed with the idle control valve totally closed or blocked off..  this is the lowest possible speed the engine can be controlled to by the ecm...

when the base idle is wrong... usually set too far closed... the computer is designed to open it more than it normally does to get it to the proper cold idle speed... this is what you are hearing...

with a scan tool on a gm... you normally see 20 to 50 idle air counts when the engine is at operating temp...      when you turn off the key.. most of the time.  the idle air control valve retracts to 80 to 90 counts.. so the engine starts cold faster.. it is ready to go..   when the base idle is too low.. the idle air control motor has to retract to over 120.. maybe as high as 135 IAC... (idle air counts)  this makes a lot of noise...

and... is the air filter and ducting on the throttle body.. most of the time... this has noise reduction built into it...


i take it that you are still talking about the Y2K dakota v6..


some times the throttle position sensor needs to be adjusted.. i don't know if it has any slots where it mounts to the throttle body.. . you need a scan tool or a digital volt meter with piercing type alligator clips on the ends to probe the wires without too much damage...  

Sorry yea I meant the dodge dakota. I hope I didn't damage the valve when I put it on, I just took it out of box and put it it, there was no resistance like if the valve was out to far. The truck does idle at about 650 rpm not sure if thats normal.