Afternoon all,

Having an issue with our Focus 1.8 petrol engine when it's stone cold.

We'll literally get to the first junction at the bottom of our road and as we dip the clutch and cruise to a stop the engine will die off. Restart the engine and carry on to the next junction (50 meters away) and it's absolutely fine, revs do drop low when we dip the clutch but it stays on and goes back up to normal idle revs. After this it drives perfectly unless it has been sat long enough to go cold again.

Does anyone know what could be causing this to happen? I'm hoping a simple sensor or something but worried it could also be the autochoke or throttle body or something.

Thanks in advance!

There’s a good chance the throttle body needs a good clean if it’s never been done. They usually do on these cars if they’re getting on a bit in age. Do you ever get a slightly erratic idle? 

 

As a work around for now, you could try letting the car idle for a couple of minutes before setting off when you’re not in a rush. It might stop it stalling at the first junction if it only does it when it’s stone cold. 

1 hour ago, Hooded said:

There’s a good chance the throttle body needs a good clean if it’s never been done. They usually do on these cars if they’re getting on a bit in age. Do you ever get a slightly erratic idle? 

 

As a work around for now, you could try letting the car idle for a couple of minutes before setting off when you’re not in a rush. It might stop it stalling at the first junction if it only does it when it’s stone cold. 

Yeah sometimes but again only of its still cold, warms up very quickly compared other cars I've owned though so doesn't take long for it to calm down. Yeah that's what I've been doing and it does work, doesn't even have to be long, or if traffics clear enough to get the revs up as i go down the road that also seems to stop it happening.

Just a bit of carb cleaner in and around the throttle body be ok?

2 hours ago, chopkins117 said:

Yeah sometimes but again only of its still cold, warms up very quickly compared other cars I've owned though so doesn't take long for it to calm down. Yeah that's what I've been doing and it does work, doesn't even have to be long, or if traffics clear enough to get the revs up as i go down the road that also seems to stop it happening.

Just a bit of carb cleaner in and around the throttle body be ok?

Carb cleaner is fine to use, or even WD40 would do the job. 

Ours has been doing this ever since we bought it ten years ago. About 3 or 4 minutes from the house it would get quite jerky then it would clear and drive perfectly. I've always assumed it's just a bit of poor mapping. There are never any codes in FORScan.

Having said that it does seem to have got worse recently and on one occasion after starting the revs stayed very low and it was reluctant to respond to the accelerator so maybe it's time to give the TB a clean.