Hi this is a problem i have known for long .

Not only with my own car but others also. With this engine from around the same year. There are no foult codes . Everything seems to be working perfectly.

What happnes . 

When i accelerate between 2000 and 3000rpm. You feel a loss of power but comes back then again loses power and comes back again . At around 3000rpm the car revs fine again .

This you can feel most in 3th 4th and5th gear. It is also felth more when engine is warm.

I did feel this with other cars . Today same thing focus 2009. Same problem. 

Most dont even feel it or never put the pedal to the floor. But to me its anoying 

Does anyone had this also . And hopefully a solution

 

I'd do a leak off test on the injectors, if they are faulty and leaking off too much it can cause loss of power without logging any codes. 

same year as my car and size i had somethink like that,it was down to a fuel filter got a new one stuck on works ok now

Hi thank you for the insight .

The injectors i would say no becous the car has this problem almost since new. 

Altho never took injectors out .

Fuel filter is not the problem.yes it can couse loss of power and had this problem also before on a different focus. It dous not feel the same like this. 

Iff its the fuel filter the power dous not come back after 3000rpm .

This is only between 2 and 3000rpm that you can feel it. 

If been like it from new, only things I can think of is it's either the standard map on these vehicles and thats the reason you've felt multiple cars do it. 

Possibly the A/C compressor cutting in and out to give engine more power on acceleration. (I used to feel this on my 1.25 as it wasn't a very powerful car I could tell the difference). If the A/C is off does it still do it?

As it's a diesel it could be  the EGR opening and closing, never known this to cause this issue though. If it's stuck open then you'll have hardly any power at all. 

That's all I can think of for this vehicle/engine. If you've noticed it on other vehicles and they're not "faulting" either I'd sway more towards its just how they run

Hi thank you for thinking with me here.

The AC isnt the problem . Tought of that also but there is no difference on or off .

Egr would be strange iff it is stuck id feel it more and not only between 2and3000rpm

Pcm has the latest software. I did overwrite it again. And still the same.

Maybe build a different map for the car . Im gonne keep this car for at least a couple of years and really want this solved now

I share this info may be help others with the same issue. It is  Egr sensors or hose lekage which missleading the egr calculation. So Egr opens and shuts continusely at 1.9- 3000 rpm.