Rough/Stalling on idle?

Scottland

Scottland

Scottland

Soldato
Joined
18 Oct 2002
Posts
15,713
Location
North Wales
The Mrs' 500 this morning is really rough and cuts out on idle, if you give it a little gas it sound fine and all cylinders firing.

It was only started for a minute yesterday when she checked her washers were working, and it's been pretty cold - so I'm thinking battery at the moment. Got it on a charger but will be a few hours before there's enough juice in it to try again. It looks like the original battery from 08.


Any other suggestions? Plugs were all changed a few thousand miles ago, and seems find with a little gas so not sure it's the coil packs. MAF/Lambda sensor?
 
does she like to run the tank low?

i used to have a car that sucked up the crud from the bottom of the tank if you let it run into the red. had to give it a boot-full to get it to clear.
 
neil_g said:
does she like to run the tank low?

i used to have a car that sucked up the crud from the bottom of the tank if you let it run into the red. had to give it a boot-full to get it to clear.
Click to expand...

A friend of mine says this is a old wifes tale And that the fuel pipe is at the bottom of the tank so it makes no odd and thays what fuel filters are for
 
cjgardens said:
A friend of mine says this is a old wifes tale And that the fuel pipe is at the bottom of the tank so it makes no odd and thays what fuel filters are for
Click to expand...

i dont know if was crud in the bottom (giggidy) or crud thats floating maybe so when it got too low it got sucked up clogging the filter.

i dunno, just whenever it ran low it used to run like a bag of spanners even when you refueled and stalling on idle until you gave it a high rev and it backfired and cleared.
 
neil_g said:
i dont know if was crud in the bottom (giggidy) or crud thats floating maybe so when it got too low it got sucked up clogging the filter.

i dunno, just whenever it ran low it used to run like a bag of spanners even when you refueled and stalling on idle until you gave it a high rev and it backfired and cleared.
Click to expand...

I know when petrol is left for a long time it goes funny. Looks like man juice haha. that does float as well. But if your using the car all the time I dont think it would happen.

Also what I have noticed is that when I get fuel from different places the quality isn't always the same and my sisters corsa had a simular issue to OP with some tesco full about a year ago. Could be a few things I'm no expert
 
Only 3 things needed for combusion, as you have (seemingly) ruled out spark, other people have mentioned fuel I shall mention air.

I know on my car (Ford) in cold weather the idle air valve can stick closed meaning it wont idle without a little throttle. I don't know what system Fiat use for idle air control but possibly a similar sort of problem.
 
Indeed, on my old car, a Fiesta 59 plate, I had problems with idle revs being all over the place and the car stalling when idle. It was bad enough to stall when I was approaching junctions/lights/roundabouts and I put the clutch in to change to neutral.

On that car there was no idle control valve but it did turn out to be the throttle body which would also be responsible for regulating the airflow. It was only a £40 part, only 4 screws holding it on and it was a 2 minute swap. Could be a similar thing on this.

Took it to a main dealer twice and they said they couldn't find a problem both times, yet both times after driving it off it stalled within seconds. Idiots clearly didn't even bother taking it for a test drive and just looked for fault codes. Clearly they didn't even bother firing the car up either as they would've seen the revs bouncing all over the place and fluctuating between 500 and 2000rpm. Only decided to swap the throttle body myself as I had no other ideas.
 
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Faulty temp or maf sensors can cause idling problems when it's cold. A cheap one reader can tell you what temp the car thinks the air and water is. Easy way to check it's working.
 
Throttle body intake controller/flap thingy can be cleaned once the air intake pipe is removed, along with the surrounding intake bit.

Sorted out the idle on my focus.

l
 
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