Startup Fast Idle
 

I own a 2004 F-150 4.6L. I cleaned the throttle body and the map sensor both with the correct cleaning fluid. Now when the truck is started it goes to 1600 rpm and slowly works down to 800 or 900 rpm. This can't be good for the engine on cold start....


Any Ideas?

Craig

The IAC might need cleaning to. Have you checked to see if any vacuum lines came unhooked?

Idle air control Location
 

Yes I checked the vacuum lines...where is Idle control valve located in this truck?

Thanks,
Craig

my 5.4L does it too even at 10° below.

has it not always done this? its just the high idle at warmup. sounds normal to me

High idle
 

Its never been this high, maybe 1200 rpm...

Craig

My 5.4 start up idle is 1200 and my dads 4.6 idle is only around a 1100 rpm so 1600 may be a little high.

I have a 2005 STX 4.6 liter. I don't have a Tac so I can't tell what the rpm's are at startup but mine has always idled high at startup. Especially the colder it is. Less when the air temperature is warm. I figured this was normal.