My car seems to idle really low and when i come to a stop and pop it out of gear it almost cuts out.
Also i have noitced that on idle it seems slightly rough and the engine almost rattles as its too low. The headlights occasianly flicker at night too.
Also something that might be worth mentioning is that from a cold start it 'hunts' badly.

I have so far replaced; The idle speed control valve, Breather pipe (which had collapsed) at the back of the engine the vehicle had a full service (including plugs) less than 2,000 miles ago. I am considering the PCV vlave or speed sensor next?

I have attached a picture of the idle to give an example, this is once the cars warmed up.



Any help would be much appreciated.

 

I see thats a Focus by the piccie, there is someone else who has a similar problem at the moment on here, to me that sounds like an air leak (As his does) Check the hose below the inlet manifold there is a T piece as well, this is well known for splitting, believe it to part of the PCV.

Martin

 

Havent mentioned the fact that i have a stainless exhaust manifold and de-cat, because i am 99% adamant that the bad idle started before i fitted this system, however the mrs was saying last night she dosent remember me moaning about it untill after...... i am thinking this may be the cause because the ECU's post cat sensor is picking up emmissions that are too rich?

 

as martysmartie said, there is a breather pipe below the inlet that is a common problem.

There is a chance it could be the VSS on top of the gearbox

 

So you dnt rekon the manifold would have made any difference to the idle, the MIL is out. Ive replaced the breather pipe that goes from the back of the inlet manifold to the metal pipe that then goes to the PCV valve which i have checked and is fine. sorry to be thick but what is the VSS on top of the gearbox?

 

is it a zetec e engine or zetec s ??

the cht (cylinder head tempreture) sensor can cause this,
as can the affor mentioned spliting of the crappy rubber pipes in thebreather system

 

Its a 2.0 Zetec-e

 

Vehicle speed sensor, its on the box somewhere may not be the top though lol.

I only thought of it because of your comment of nearly stalling when coming out of gear

 

You can check the VSS by simply driving at say 25mph at putting into neutral then foot off the clutch it should hold the revs around 1400rpm, this is done to help make gear changes better, if VSS is duff it won't hold the revs up.
What did you do with the EGPDS when you fitted the exhaust system ?
tabetha

 

I will have to give that a go Tabetha, what is the EGPDS?

 

EGPDS = exhaust gas pressure differential sensor, a electronic box on the bulkhead in engine bay joined to the exhaust by 2 small rubber pipes, and a lecky multiplug, if this is unplugged it can spas some systems out, others it doesn't affect, seems to be luck of the draw, my mondeo went into los(limp home mode) when disconnected.
tabetha

 

I'm pretty sure I don't have that!? When I replaced the manifold the ony thing attached to it was the to lambda sensors.