Car sometimes stalling

[Somewhatfoolish]

When going from idling to very low throttle then to zero throttle - then the stall. It seems to only happen if the engine is warm, yet has just been started in the last couple of minutes. This also seems to happen in "phases", e.g. it's doing it today and will probably do it for a couple more days, then be fine for a fortnight.

What could possible causes be? I'm not particularly fussed so long as it's nothing serious, because it isn't dangerous at the times it happens.

[Gwagon111]

Airflow meter / air mass sensor / MAF sensor is probably dicky.

[anonymous-user]

Also could clean ICV - Idle control valve.

I know thats on bmw's dont know about your car.

[Gwagon111]

duckhunt said:

Also could clean ICV - Idle control valve.

I know thats on bmw's dont know about your car.

If its a ford, with a Zetec engine, that's also a good call.

[MondeoMan1981]

Any rough running? Any dash warning lights?

Could be a coil pack also. My Mondeo wouldnt idle and would cut out when its pack developed a crack.

Called RAC, they came along, plugged in, confirmed and fitted one there and then for the price of the part only !

[varsas]

My first thought was idle air control valve or a cam/crank sensor (although faulty sensors show up at any time, you'd get a loss of power at any time not just at low revs). Would help if we knew which car it was, if it's a 1967 MGB it's more likely fuel vaporisation then a cam sensor!

I've seen a few of these threads and I know people are trying to be helpful but really, I don't know why the first step would be anything except read the ECU codes. Why guess at what the problem might be when in all likelihood the car itself knows exactly what's wrong? Even a lack of any error codes is very enlightening. If it's ODB you can probably read it by shorting a couple of pins on the ECU plug, if it's ODB2 just get a cheap reader.

ETA in my experience a fault with the IAC valve doesn't show up as an error code!

[davepoth]

Gwagon111 said:

duckhunt said:

Also could clean ICV - Idle control valve.

I know thats on bmw's dont know about your car.

If its a ford, with a Zetec engine, that's also a good call.

Doesn't need to be a Zetec - it's the same (crap) design across all the models between the mid 90s and the mid 2000s IIRC - certainly it was on the '98 Fiesta 1.3 I had.

[varsas]

davepoth said:

Gwagon111 said:

duckhunt said:

Also could clean ICV - Idle control valve.

I know thats on bmw's dont know about your car.

If its a ford, with a Zetec engine, that's also a good call.

Doesn't need to be a Zetec - it's the same (crap) design across all the models between the mid 90s and the mid 2000s IIRC - certainly it was on the '98 Fiesta 1.3 I had.

Vauxhalls are well known for it too, had to clean mine out every 2 years or so.