Hey guys, like the title says, i will be driving and as i come to a stop my rpms will drop to about 500-600, now it wont do it all the time , jst sometimes, i would say at least once in every 10-15 stops. I have a 5 spd and it does this when i am in neutral coasting to a stop or if i have the clutch in if that helps.

any thoughts?

 

IAC.. my truck does that every now and then

 

mine did that..my MAF was shot

 

Take some MAF cleaner and clean the MAF and IAC, see if that helps ya out

 

be careful tho..extremly careful

pretend its a bomb

 

what do i want to avoid doing? breaking it? or getting cleaner in something? lol if its that meticulous than i can live with it

 

what engine do you have I have two differnt 4.0 with a 5spd and they both just idle at 600 700 and the O2 and MAF I always new that as normal But i dont hav the ovc either i supose

 

he's got the 2.5L I4

 

never touch the actual sensor..dont get it wet dont be rough with it.. just use care with it..

 

I'd say it's the IAC valve. Napa has a fairly inexpensive (compared to ford) replacement. I tried to clean mine but it didn't make a difference.

 

The IAC is a posibility, but keep in mind that the clutch cancel switch signals the processor on these trucks and it will affect idle, as will engine temp. (I've seen some problems with after market air intakes and filters causing this type of problem).
I would do a computer scan first, also be sure there's no codes and that the throttle body and IAC are clean, and that the base idle is set properly. Also make certain that the engine is reaching full operating temperature, a stuck thermostat will also cause an irratic idle. Idle is kept slightly higher when in gear and driving for both emissions and drivablity purposes. Stepping on the clutch or shifting to neutral both signal the ECM that the engine is no longer under load. The clutch cancel signal is used for this as well as the canceling of cruise control on some vehicles.

From your description, it sort of sounds like maybe the IAC is not working or that the throttle body is dirty. Both of which will reduce true base idle and let the RPMs drop below spec when the ECU calls for a minimum idle.

If it were mine I would first scan it for codes and check the airfilter and throttle body.
The IAC can sometimes be cleaned, but cleaning won't fix one that's simply quit working. The MAF sensor can be cleaned, but the actual element is very fragile, it sort of looks like the filament in a light bulb. You can clean it with MAF cleaner in a spray can, or if your super careful, some alchohol on a Qtip. I would also make sure that the air cleaner is clean as well, this can also affect idle quality

 

it is the IAC. mine did the same exact thing before i replaced it