IAC valve adjustment

[kinger]

Hey guys,

I'm tracking down a idle problem on my sled where it oscillates revs every 3 out of 4 starts.

There is a adjustment screws on top of the valve labeled 1,2,3,4 but I cannot locate any adjustment info in the manual, is there a adjustment and would it be different when the supercharger is installed?

Lastly is the IAC something I should clean?

The sled has 3500 miles.

Thanks

 

[HURRICANE]

I have a vacumm hoseset up as a take off from an Apex.You can have it if you like for the shipping.
Dave

 

[kinger]

Bump

 

[mbarryracing]

kinger,

Those four screws oriented in a square on top of the IAC valve are the individual flow adjusters for each idle air supply hose going to each individual throttle body port. Used to sync...

I tried cranking mine open to get my idle AFR's up a smidge but I think it subsequently affects the MAP reading with a lower vacuum (less restriction)...

BTW, the IAC on these is like a thermostat, has wax that expands slowly when the coolant temp increases and moves the pintle to close off the air flow. It doesn't move or react fast, so wouldn't think it could cause an oscillation like an electronic stepper motor type (that reacts fast) does...

 

[kinger]

all of my ports are tied together so do the screws do anything important?

 

[mbarryracing]

You changed it from the stock configuration? Each separate one should run to the IAC valve manifold...
Not talking about the small vacuum ports for the BOV, etc.

 

[kinger]

Good question I didn't do anything its my craigslist special and will be pulling it apart to replace all the vacumn hoses soon and just wanted to see if there was any way the IAC valve coudl be adjusted, cleaned, etc that would help my osilatting idle problems.

 

[kinger]

Dave - Thanks for the hose set! I am going to install it tonight. One question did this come off a stock apex what year? I only ask because its not configured the same as mine or the picture in the MPI manual the "T"'s are in different spots, etc.

Thanks again, hopefully this fixes it!