(a boring one)> 2009 Focus 1.8 petrol, poor idling advice

[andymc1973 199]

The car has 83k and has had a recent service, from time to time the car idles roughly and almost cuts out until the engine kicks in with a few extra revs, would you start with cleaning the throttle bodies or are there more common faults on these?
Seems ok on a cold start
many thanks as always 
Andy

seems to clear after a few miles

[Stalker 180]

Hi Andy

 

From memory, breathers under the inlet manifold are prone to either coming off or perishing.

Get it on a smoke machine to look for a leak ideally.

[andymc1973 199]

Cheers, for some reason it’s more evident when driving 

[andymc1973 199]

clearing the throttle bodies seems to have helped. thanks

[metcars 395]

On 05/11/2018 at 6:12 PM, andymc1973 said:

The car has 83k and has had a recent service, from time to time the car idles roughly and almost cuts out until the engine kicks in with a few extra revs, would you start with cleaning the throttle bodies or are there more common faults on these?
Seems ok on a cold start

I've got a 1.6VCT that does exactly the same, fine when cold but randomly idle starts bounching until you touch the gas. Feels sluggish. It usually recovers after a while and no codes or EML. O2 sensors and trims seem fine and no vac leaks. I was wondering if it's the MAF?

[metcars 395]

Just now, tradex said:

If you can read real time data check if air mass looks sensible. 

It sometimes sounds a little 'tinkly' on an open throttle and lumpy at idle. But yeah I'll have to dig a bit further.

Don't want to turn this forum into Piston Heads?

[twerp 69]

VCT engine can be a lot of trouble with the variable timing system.

I remember a vanilla 1.6 Focus that had a terrible time when cold with the symptoms mentioned above in the thread.

Turns out the weather was leaking through the seals of the washer jets directly beneath onto the leads and plugs. 

Bit of silicone sealant to plug the leak and dried everything out and it was 100%

[metcars 395]

2 minutes ago, tradex said:

We have had inlet manifold gaskets harden on these causing air leaks, not very common but have repaired two, similar symptoms when everything else checked out. 

Did you get an accurate diagnosis of a inlet manifold gasket or just take a gamble?

[metcars 395]

1 hour ago, tradex said:

Well it's more rubber (nitrile) O rings but a quick and dirty check is using good old fashioned carb cleaner, being very careful where....I not going to tell you how to suck eggs

Don't worry about that, i'm not proud! Lol