Only thing I can think of is a vacuum leak on the manifold. Once it heats up it seals and the problem goes away.

 

vacuum leak? if the manifold is past the throttle and is leaking, the manifold pressure sensor is going to see that. and if it sees more air than necessary, shouldnt it try to close the throttle more? and if its a manifold leak, why would it just affect the rpm when the clutch is pressed.

 

I know its weird. When ever I have seen something heat related like this I have found it is some type of sealing surface. Also, with a mass air for system the engine like the ST it should reduce speed with a vacuum leak. With speed density it should increase.

Other ideas I was thinking about is maybe it is something to do with the throttle valve. On engines with IAC motors the computer will go to almost zero duty cycle when shifting. It uses the clutch switch as an input. The ST doesn't have an IAC so instead it does it via the throttle actuator. When it gets cold maybe something is binding or there is a lot of carbon build up on the valve causing it to stick open more.

The computer on the ST does also hold the RPM when shifting. It sounds like it is trying to hold the RPM, but something is causing a miscalculated air fuel mixture. I would want to see the fuel trims when this is happening and see if it is in open or closed loop.

 

https://www.focusst.org/forum/focus-st-discussions/128706-rpms-actually-increase-clutch-2.html

This sounds similar.

 

Mine does the same thing recently even on a cold start. I'll be in neutral push the clutch in and RPMs go up maybe 200 RPM. And I hate the Rev hang. It is so annoying.when you go to shift in the RPMs never dropped you have to shift like a grandma.

 

I don't want to look incorrect, I cherish the knowledge I do have. Haha

 

I'm looking back at the qouting system and I don't know if they need to work on the coding for the site, but they aren't qouting correctly, it's saying qoute from xxxx: but then putting statement from someone else's post, it doesn't seem to qouting the correct info. I see it alot.

 

Yeah, i wasnt quoting you. The quote and mention system is on the fritz.

 

Has anyone encountered this? I recently started noticing an issue whenever I drive the ST after a long cold soak (3-4 hrs). RPM elevates by 2-3k everytime I press the clutch, then after a clutch pedal release it slowly bleeds down.
This is really concerning and I am not sure whether this is an issue with the clutch or the pedal or the throttle body or just software in general or something else altogether. The issues goes away in the subsequent trips after the engine is warmed up.

Did you ever find out the issue? My 2017 focus is doing th same thing

 

The problem is with the throttle pedal assembly. They're bad about sticking sometimes, so you need to remove it, pull it apart (I used small screwdrivers at each of the clip-together points to release it a bit at a time), and put some white lithium grease at the pivot points and locations where things slide together. I had to do this to my 2018's a couple years ago and haven't had a single instance of it climbing since.

 

Thank you! I took it in to the ford dealership and they told me it was the freakin purge valve. Ended up paying $600 for nothing. Wish I woulda found this thread 4 days ago.

 

Wait.. the purge valve is supposed to be a TSB/recall item. They shouldn't have charged you for that.

Ford Makes Another Embarrassing Focus ST Mistake

Focus ST owners will want to read this.

carbuzz.com

 

I mean they pulled the VIN so I guess it wasn’t in the list of cars that was in the recall. Not really sure. Kinda want to call them and find out.

 

Could be that or could be the "rev hang" that is prevalent with the stock tune. What mods have been done to the car?

 

Could be that or could be the "rev hang" that is prevalent with the stock tune. What mods have been done to the car?
[/QUOTE
thinking again I have no lift shift active on my tune could that be causing it?

 

Its stage 2 and the tune seems to do nothing. but its not like the revs are just hanging when i engage the clutch it jumps probably a 1000rpms. but not when I'm going slow

 

when i engage the clutch it jumps probably a 1000rpms. but not when I'm going slow

If this happens when you are letting off the pedal, then your clutch is probably smoked

 

You're running the Cobb ots stage 2 tune?

 

Ya ,it has no lift shift active could that be causing this?

 

Maybe you just need to lube up the pedal like it's Saturday night.

Throttle hang

What’s up guys ! So I’m having a issue when coming to a stop my cars rpm’s go up a little without me putting my foot on gas pedal it happens from time to time im sure this is common if someone can help that would be cool. Iv looked for info on here put can’t seem to find a answer. As always...

www.focusst.org

 

Maybe you just need to lube up the pedal like it's Saturday night.

Throttle hang

What’s up guys ! So I’m having a issue when coming to a stop my cars rpm’s go up a little without me putting my foot on gas pedal it happens from time to time im sure this is common if someone can help that would be cool. Iv looked for info on here put can’t seem to find a answer. As always...

www.focusst.org

Maybe but it doesn’t do this when just casually driving only when hard accelerating