Sucking air sound

[slo1]

Ok my newest problem is I'm getting a sucking air sound when the throttle is pressed while driving its worse
when I mash in the clutch the rpms shoot up 500 to a grand before going back down. I have a stock tb
and stock intake. I have put two new iac valves and two new tps on it and still the same I have pulled the upper intake and
no leaks almost sounds like it between the motor and firewall I've checked all vacuum lines and skeeted carb cleaner and starter fluid
on every line/hose and everywhere where there could be a vacuum leak. I haven't replaced the pcv valve but have cleaned the screen ill replace it tomorrow Ive had this problem for 3 weeks maby and cant seem to find the solution it isn't heard out side the car someone told me I needed a restrictor plate on the iac valve but don't make since to me any help will be greatly appreciated. I'm getting tired of this car seems like soon as I get
one thing fixed I have another problem its never ending seems like. Its almost got me to the point of wanting to sale it but Ive got to much time and money in it

 

[two95s]

Does it still have the factory air box?

 

[slo1]

I'm sorry it has bbk cold air but has had it for the last 6 months and has never done this it just all of a sudden started

 

[Lee12609]

let the car warm up, pop the hood and unplug the IAC. go for a drive. if all symptoms are gone then you found the problem.

if you are using part store iac's you're asking for trouble.

 

[slo1]

Ill try that I bet that's it

 

[slo1]

I drove with it unplugged it did great the sucking went away completely and rpms dropped as they should. I went to ford and got a new one and seemed to help a little the rps drop a little faster and the sucking air isn't as bad but not near as quiet as when it was unplugged guess ill go with it like it is for a while Thanks for the help

 

[birel21y]

Its not always the IAC. your IAC is compensating for something. If your timing or air fuel mixture is off, it may run more open, hence the "sucking air" sound.

-Alex

 

[slo1]

I know the timing is correct but the a/f I'm not sure of I know it a little rich I'm waiting till I get another intake to get a tune I'm thinking about leaving it as is till the tune and just letting them fix whatever needs fixing.

 

[Lee12609]

how is your idle with it unplugged???

you probably just need to set base idle with it unplugged. i've seen the IAC bleed screw misadjusted causing the same problem.

 

[slo1]

it dies when its unplugged it will not idle at all unplugged

 

[Lee12609]

thats the problem. with the car up to temp it should idle fine with the IAC unplugged.

you need to adjust the throttle stop screw until it will idle unplugged. the IAC is there to prevent stalling under load, decel, ect, its not designed to keep the car running.

take a look at the IDLE sticky up top.

 

[ttocs]

I have had the same noise for some time and just thought it was the CAI, what is the IAC?

 

[95-stang]

The "Idle Air Control" unit.

 

[slo1]

It seems to be doing a spy better ill adjust the throttle stop when I get home I'm out of town working till sat thanks for all the help you guys are great

 

[Paul]

Was Handz nearby? A loud sucking sound usually emanates from his location.

 

[CC'S95GT]

^^^^^lol

 

[ivan12]

Is there a story between Paul and Handz? Guess I haven't been on here long enough

 

[slo1]

Nah no handz was needed