98 f150 ext cab 4x4 cold air intake problem..help

[duece]

i installed a cold air intake on my 4.6 lt and approx two weeks later i have this sound that sounds like a air pump doing something funny (very loud) and makes the rpm's go up and down ..anyone have this problem ,know whats going on or know a fix....hopefully i explained this right..thanks to fx4 matt for the invite tothis site..sorry for not saying hello first guys..great to be here.

[fordtough.ca]

PM SKRWZ
He is expert on them
Make sure you tell him what model do you have

[SKRWZ]

First:

welcome to the site:icon_biggrin:


Second:

What CAI do you have?

How much milige is on the truck?

You may have a dirty IAC Valve

Are all the connections tight?

You may have a vacum leak

[duece]

its an in expensive brand i bought off of e-bay..i think i paid about 80.00 came with polished pipe fittings clamps hoses air filter and heat sheild,the truck has approx 160.000kms on it runs good i just put dual exhaust on it to..everything seems to be tight and assembled well..i dont think i have any vacuum leaks ..whats a iac valve?? sorry

[SKRWZ]

I would check all vacuum lines, Pcv, hoses, elbows etc for leaks/cracks etc check the rubber elbow on he pcv line that plugs in the back of the intake that one is famous for cracking, also check for a clogged PCV valve,
you can tap on the IAC valve (idle air control) with the engine running it may be stuck and in need of replacement or cleaning, on a 4.6 I believe it is beside the throttle body


IAC valve pic

http://i174.photobucket.com/albums/w88/skrwz/iac.jpg

[SKRWZ]

PM SKRWZ
He is expert on them
Make sure you tell him what model do you have


Expert...LOL

[duece]

thanks for all the great info i will try those tips and let you know,thanks again