Idling

[Johan.grundlingh]

My 2008 Fiesta st ìdle on 2000 rpm and stop by robot go back to normal idle where can i still look at

 

[Handy Andy]

2008 Fiesta hmm - did you clean - or have the Throttle body cleaned recently?

 

[Johan.grundlingh]

Hi not yet do you say i need to clean it a bit

 

[Handy Andy]

Well, to be honest _ I am only asking because of several factors..

Age - not knowing any general idea of mileage...

What brought you to this site? Did this problem just occur or is it a chronic problem and seems to happen more frequently and would like to know why it does this.

A gradual onset - where the idle kicks up only now it kicks up EVEN MORE. That condition you're now having can be several things wrong - in ways a signal (or red flag) that;

• you're developing a vacuum leak and the engine is attempting to compensate the now extra air past the throttle - only thing is that; the throttle is already closed off - the PCM is having a why is this happening moment.
• Throttle body has not been cleaned and is stuck or dirty...
• PCV valve at that age, and the hoses to it - can need service
• If your have an Automatic transmission - EGR valve may be close to getting plugged or stuck.
• Might want to locate the OBD II Connector and get/buy/borrow a Scan tool and see if you have something more going on. I/M monitors can help tell a story of what is passing and ok, versus what is not passing and is getting ready to light the Check Engine light on the dash.

 

[Handy Andy]

To help tie these two posts together...

The above list isn't complete - just some thoughts as to why the issue of having the Throttle Body cleaned is a way of knowing the CONDITION of the engine.

If you have taken the stance of leave it alone, left to the mechanic, then perhaps the cleaning job is best left to the professional to do this...

Well, if you have or have not cleaned the throttle body - it's time to remove that air cleaner filter cover that snorkel and then that opens up the throttle body in which you can peer down into the bore and see if dirt, debris - a dead mouse or acorns are jammed into the throttle plate.

IF you have recently cleaned it - better check and make sure you've seated it and the power connector it has is properly seated.

If you haven't done any cleaning and are willing to get some dirt on you - then by all means look locate, remove those parts just mentioned and dig into finding what might be causing this.

But to run back to the first message, I mentioned the cleaned part, is because when the throttle body is cleaned up from all the air dirt particles and oil residues, the spacing of the throttle plate to the bore is different - let's more air in. When you drive and use the Fiesta it has a method it uses to determine if the bore debris' is getting in the way of the quality of idle it can produce - so it does a process called "seeking". Seeking refers also to "hunting" or zeroing - you'll sometimes see on start up -the dashboard "pods" RPM and Speedo needles "bounce" then "settle" into their "Zero" position - this is like the older analog days of Wind and Weather gauges - Barometers - the old guys used to "tap" the case of the meter and make the needle bounce to free up any sort of tension or unstick a stuck needle to show correct air pressure direction or speed. Same can be said for the Throttle body.

Only the PCM is doing it to "check itself" because it thinks something happened - before you notice it. So the throttle revs up and down because it is seeking - and when it does this and you've cleaned it - then the system needs to retrain itself.

BUT

IF you have not done anything to it -the throttle body may be sensing a plugging, sticking or otherwise poor idle quality condition so it learns to adapt to it.

It's this latter condition that - if that is the case - then you need some one - you or mechanic or both of you - to go over the reasons for why this idle is happening.

Nothing stays clean forever - so this may be a good time to have the mechanic look into cleaning the throttle body, and then letting the vehicle retrain itself.


There are several YT videos about Ford throttle Body Cleaning and Ford Throttle Position Relearn process.