Engine Idles High - Need Help!

[Bluepolo3]

I have a 2005 Sport Trac with 98K miles. When I key on the vehicle the engine idles high (around 2000-2500 rpms). When I shift into gear the rpms drop but vehicle still seems to be idling high. Any suggestions on what I could check or need to fix? I was thinking the IAC valve but was not sure. Thanks!

 

[MyTrac]

That seems to be normal upon startup. However, if it stays there after a little bit that is bad. Mine starts and goes to about where you say but drops to 1000. After a couple seconds...it lowers to the lower idle. I would just try and clean the MAF and the IAC. I had alot of carbon in mine and it helped. ALSO a treatment of seafoam before winter would be very beneficial. make sure to use the whole canister of seafoam as well.

 

[swshawaii]

Ditto. Also clean the throttle body.

 

[roamer37]

Vacuume leak letting unmetered air into the intake past the throttle body

 

[MyTrac]

If there is a possible leak, spray carb cleaner around the throttle body and see if the engine revs. Tighten down the clamp around the throttle body. I have seen people even put like a silicon caulking around it. I wouldn't do this myself but maybe someone else may find it to be a good idea....

 

[Holleyman]

Check the rubber elbow on the front left of the intake vacuum line that goes to the PCV valve. These rubber elbows tend to crack and cause idle issues and throw banks too lean codes as well

 

[Bluepolo3]

Thanks for the help. I checked the DTCs and a "P0507 Idle Control System RPM Higher Than Expected" was set. I will follow what the above posts have but if anyone has any other ideas please share! Thanks again for the help!