Idle rev adjustment

[MacWopp]

Apologies for this i know absolutley nothing about cars but a relative suggested this is something to do with adjusting the revs or fuel to air mix? I dont know. 

 

Sometimes only when im not in gear the revs stutter down to say 300rpm sometimes it cuts out sometimes it goes back upto 700 where it usually sits. I notice it more when im reversing into a space going from 1st into reverse it struggles or when its started first thing in the morning i let it run abit and it does it. 

Also if its idle and rev it to 1500-2000 its fine but anything below that again just stutters. 

Any suggestions? 

Anything i can try on my own? 

Id rather avoid taking it to a garage right now as im going on holiday in a few weeks and a huge machanic bill is the last thing i need right now as its going in for an mot in 2 weeks. 

 

1.6 focus mk3

 

 

Thanks! 

[artscot79]

idle cannot be adjusted you'll need to find the root of the problem first

[Tdci-Peter]

Don't know whether Diesel or Petrol.

The days of adjusting screws for air fuel mix or idle have long gone. All electronic now.

If Petrol, suspect idle valve or throttle valve (not sure if Focus has a separate idle valve or just uses the main throttle valve).

If Diesel, suspect EGR valve maybe.

But in either case, electronic or wiring problems may be the cause. If so there may be error codes. See my reply to:

 

[Dee_82]

Dirty MAF can make the idle rough but I don't know if it could be bad enough to stop the engine, I guess It could though, I the ECU didn't "see" the air coming in it might shut the engine down.