Stalling at low speed - anyone help?

750-t · 10th December 2010, 16:35

Hi,
I have searched this forum and read through many posts but can't seem to find one that came to a satisfactory conclusion, so I will have to post my own problem:

My car is a 1.8T ZT-T and the problem is that it tends to stall at low speed when slowing to a stop. This obviously makes the power steering and brakes harder to operate and is a bit of a concern, especially if you are turning slightly at the time!

It only happens soon after it has been started up from cold and it always takes a while for it to start again straight afterwards - the starter keeps turning over and I fear it won't 'catch'/fire up again - although it always has. (so far) The strange thing here is that it has always fired up first time prior to it stalling!

My wife has also complained of rough running/lumpyness whilst the engine is still cold but I haven't experienced that myself as I don't drive it as often.

None of these problems occur once the engine has warmed up and it runs just fine.
As it only seems to happen when it's cold I think it's temperature related but because Im not really sure how all the engine sensors interact I can't be sure.

Anyway, no fault codes show up and the stepper motor (Idle Air Control valve) has been changed, but the problem is still there.
I don't think it will be related to the injectors as surely they would cough and splutter a bit rather than just suddenly cut the engine stone dead?

Anyone got any ideas? They would be much appreciated -this is really bugging me.

Thanks,
John

Cymrudragon · 10th December 2010, 16:49

Sounds like a coil pack is playing up or a fuel problem....

does it lack power at all? and what is the history , what parts have been replaced recently...etc
but a sensor may still be the prob eg crank and cam..

empsburna · 10th December 2010, 17:11

Does it do it when you slow down and put your foot on the clutch?

750-t · 10th December 2010, 17:47

In response to the questions :-

Cymrudragon
"Sounds like a coil pack is playing up or a fuel problem...."

In that case wouldn't there be constant problems?

In my case there are no problems once it has warmed up and no problems with the acceleration or at high speed.

No fault codes show up, the stepper motor has been replaced a week ago, the HT leads/plugs were replaced 5 months ago and it had a new head gasket in the distant past.

------------------------------------------------------------------------

empsburna

My wife says that it does stall when she dips the clutch to change down (at low speeds) whereas I myself have only had it stall on me as I'm slowing down to a stop, or just slowing down at a T junction ready to turn.

Can you enlighten me any further?

Thanks all,
John

empsburna · 10th December 2010, 17:54

Sounds like the coolant temp sensor. Very common. Usually you have a noticeable drop in MPG.

750-t · 10th December 2010, 17:59

Thanks empsburna, that's interesting.

Just out of interest ... why did you ask about the clutch?
Is there a connection there as well?

empsburna · 10th December 2010, 18:08

Not related, just a symptom. Used to change mine pretty much yearly as a service item. Last time I had one it was about 12 quid. You can test them with a multimeter.

James.uk · 10th December 2010, 18:11

Sounds to me more like a choke problem, except modern cars don't have one...

But they must have something that does a similar job??? i.e. adds more fuel to a cold engine??
...

Synchromesh · 10th December 2010, 18:17

Quote:

Originally Posted by empsburna

Sounds like the coolant temp sensor. Very common. Usually you have a noticeable drop in MPG.

If the coolant temperature sensor is faulty does it result in an OBD temperature reading that is obviously incorrect?

750-t · 10th December 2010, 18:55

Good question Syncromesh - does anyone know a faulty Coolant temp sensor would show up in the OBD?

Also, could the Intake Air Temperature sensor be involved here at all?
(I must admit I've looked under the bonnet and can't even see where it's located!)
Can anyone give me any pointers where to look?

10th December 2010, 16:35	#1
750-t Newbie ZT-T Join Date: Jul 2007 Location: London Posts: 8 Thanks: 0 Thanked 0 Times in 0 Posts	Stalling at low speed - anyone help? Hi, I have searched this forum and read through many posts but can't seem to find one that came to a satisfactory conclusion, so I will have to post my own problem: My car is a 1.8T ZT-T and the problem is that it tends to stall at low speed when slowing to a stop. This obviously makes the power steering and brakes harder to operate and is a bit of a concern, especially if you are turning slightly at the time! It only happens soon after it has been started up from cold and it always takes a while for it to start again straight afterwards - the starter keeps turning over and I fear it won't 'catch'/fire up again - although it always has. (so far) The strange thing here is that it has always fired up first time prior to it stalling! My wife has also complained of rough running/lumpyness whilst the engine is still cold but I haven't experienced that myself as I don't drive it as often. None of these problems occur once the engine has warmed up and it runs just fine. As it only seems to happen when it's cold I think it's temperature related but because Im not really sure how all the engine sensors interact I can't be sure. Anyway, no fault codes show up and the stepper motor (Idle Air Control valve) has been changed, but the problem is still there. I don't think it will be related to the injectors as surely they would cough and splutter a bit rather than just suddenly cut the engine stone dead? Anyone got any ideas? They would be much appreciated -this is really bugging me. Thanks, John Last edited by 750-t; 11th December 2010 at 07:24..

10th December 2010, 16:49	#2
Cymrudragon I really should get out more....... MGZTT2.5 V6 190+ SE 2002 Join Date: Oct 2009 Location: Gilfach-goch Posts: 2,201 Thanks: 0 Thanked 8 Times in 4 Posts	Sounds like a coil pack is playing up or a fuel problem.... does it lack power at all? and what is the history , what parts have been replaced recently...etc but a sensor may still be the prob eg crank and cam.. Last edited by Cymrudragon; 10th December 2010 at 16:55..

10th December 2010, 17:11	#3
empsburna Gets stuck in Other Manufacturer Join Date: Jan 2007 Location: The Black Country Posts: 716 Thanks: 0 Thanked 28 Times in 3 Posts	Does it do it when you slow down and put your foot on the clutch?

10th December 2010, 17:47	#4
750-t Newbie ZT-T Join Date: Jul 2007 Location: London Posts: 8 Thanks: 0 Thanked 0 Times in 0 Posts	In response to the questions :- Cymrudragon "Sounds like a coil pack is playing up or a fuel problem...." In that case wouldn't there be constant problems? In my case there are no problems once it has warmed up and no problems with the acceleration or at high speed. No fault codes show up, the stepper motor has been replaced a week ago, the HT leads/plugs were replaced 5 months ago and it had a new head gasket in the distant past. ------------------------------------------------------------------------ empsburna My wife says that it does stall when she dips the clutch to change down (at low speeds) whereas I myself have only had it stall on me as I'm slowing down to a stop, or just slowing down at a T junction ready to turn. Can you enlighten me any further? Thanks all, John

10th December 2010, 17:54	#5
empsburna Gets stuck in Other Manufacturer Join Date: Jan 2007 Location: The Black Country Posts: 716 Thanks: 0 Thanked 28 Times in 3 Posts	Sounds like the coolant temp sensor. Very common. Usually you have a noticeable drop in MPG.

10th December 2010, 17:59	#6
750-t Newbie ZT-T Join Date: Jul 2007 Location: London Posts: 8 Thanks: 0 Thanked 0 Times in 0 Posts	Thanks empsburna, that's interesting. Just out of interest ... why did you ask about the clutch? Is there a connection there as well?

10th December 2010, 18:08	#7
empsburna Gets stuck in Other Manufacturer Join Date: Jan 2007 Location: The Black Country Posts: 716 Thanks: 0 Thanked 28 Times in 3 Posts	Not related, just a symptom. Used to change mine pretty much yearly as a service item. Last time I had one it was about 12 quid. You can test them with a multimeter.

10th December 2010, 18:11	#8
James.uk Passed Away 2002 Pale Blue. Rover 75 CDTi Connoisseur auto. 170K miles Join Date: Dec 2008 Location: Near the M67. Posts: 14,509 Thanks: 199 Thanked 585 Times in 397 Posts	Sounds to me more like a choke problem, except modern cars don't have one... But they must have something that does a similar job??? i.e. adds more fuel to a cold engine?? ...

10th December 2010, 18:55	#10
750-t Newbie ZT-T Join Date: Jul 2007 Location: London Posts: 8 Thanks: 0 Thanked 0 Times in 0 Posts	Good question Syncromesh - does anyone know a faulty Coolant temp sensor would show up in the OBD? Also, could the Intake Air Temperature sensor be involved here at all? (I must admit I've looked under the bonnet and can't even see where it's located!) Can anyone give me any pointers where to look?