ok efi gurus, someone explain the duties of I.A.C.

[gwaii]

not quite...the throttle plate has a set screw on it,it's adjusted from the factory to be slightly open,then the screw is sealed.but most of the air needed at idle goes through the iac.

 

[cammeddrz]

the wheels in my head are turning.......

 

[adsm08]

The throttle plate is not fully closed when it is "closed". There is not enough air flow allowed for a cold engine to run on, but a warm engine can idle, albeit poorly, if the IAC fails in it's full closed position. It will eventually idle down and die that way though.


What's with all the IAC questions Cam? I thought you were a die hard carb guys.

 

[gwaii]

although the specifics will change from engine to engine,the gist of it is that if an 800rpm idle speed is wanted,the trottle plate will be set to about 550-600rpm.the iac will make up the difference.

this acts a little like the dashpot on some carbs,keeping the air from being completely shut off if the throttle is snapped shut.without the slight openning on the throttle,the iac would not have time to open before the engine died.

 

[cammeddrz]

What's with all the IAC questions Cam? I thought you were a die hard carb guy.

um what.....? my v8 bII has been injected since about 1 month after i gor it running. even my racecar was fuel injected :icon_confused (this pic was taken like 5 years ago or more):

i am considering swapping in an intake that is from a newer truck and has an iac. whereas my current setup does not. what it does have is an idle solenoid that physically opens the throttle

it sounds like i can set the idle, then take the idle solenoid wire from the ecm, run it through a poteniometer so i can adjust the voltage. and the iac will work just like my current idle solenoid

 

[gwaii]

so this explains your earlier questions about efi hardware too.


sounds interesting,keep us posted

 

[adsm08]

For some reason I thought your 350 was carbed.

 

[cammeddrz]

so this explains your earlier questions about efi hardware too.

actually you have that the wrong way around, i started that thread out of sheer curiosity, but the replies to that thread got me to thinking more and more about swapping an l-31 intake onto mine

For some reason I thought your 350 was carbed.

close, it has throttle body injection as of now.

 

[adsm08]

close, it has throttle body injection as of now.

Close enough.

 

[cammeddrz]

Close enough.

yeah but it isn't your regular tbi, it has 120 lb/hr injectors on it, with dual 55mm butterflies.

i am considering the l-31 swap