RPM's hanging after a shift?

[Matticus91]

Hey guys I am not quite sure if this is actually a problem or not so I'll just describe it.

When shifting, after getting out of a gear, the RPM's tend to go down rather slowly or they hang at the current RPM. Rarely the RPM's will actually climb a very small amount.

Now I'm no pro at shifting. This is my first manual car and I've only had it for about 2 months. So it could easily just be human error but I just want to make sure it's not a mechanical issue.

When I shift I don't keep my foot on the gas so I know that is not what's causing it. But because I'm still a noob I'll give a quick rundown of my shifts.

Up shift: foot off gas, clutch in, out of gear X into gear Y, ease off clutch and onto gas.

Down shift: foot off gas, clutch in, out of gear Y, rev to match next gear, into gear X, ease clutch out and gas on to match.

Let me know what you guys think

[mustang51js]

sounds to me it might be the iac valve, its located on the throttle body with 2 screws, or possibly the idle,but i would take the iac valve off first and clean it with some carb cleaner and see if that helps,heres what it looks like
http://www.latemodelrestoration.com/...-04-Mustang-GT

[Matticus91]

Looks like a pcv valve haha. Alright great thanks for the info! I'll give that a shot when i get the chance and post up results

[hpwrestler220]

Pretty sure this is a common thing with 99-04's...

http://mustangforums.com/forum/4-6l-...ging-rpms.html

[GT800]

yeah iacs suck they are known to go bad but when they used to start getting bad on my fox i would take it apart and soak the top half in gas for a night

[Matticus91]

Would soaking it in seafoam work the same?

[GT800]

hmmmm yeah probably i dont really see why not. Or even carb cleaner

[Matticus91]

Yeah I might just get a thing of carb cleaner. Reason I asked was i have half a bottle of seafoam left over so i figured i'd just use that.

[GT800]

i just have never used seafoam in this situation so im not 100 percent sure in

[Matticus91]

Alright i'll stop at the pep boys and see what they've got. Hopefully it works sometimes it makes it hard to shift