Stutter only when cold

[MrTurner]

Any ideas on the above? Done loads of searching, run a VAGCOM search on the car (cleared a low temp sensor fault which has not returned).

The stutter is only present when cold, within 2 mins its gone. It doesn't seem to be present at any other time I've only had the car a few weeks, so it's always driven the same.

 

[ScoobyJawa]

Wifes car was like that, did the N249 bypass and its gone!

Could be to do with the Supplementary Air Intake for emissions on cold starts, a quick search shows a lot of people have/had it!

 

[DPJ]

Faulty coolant temperature sensor could cause that.

 

[MrTurner]

Cheers guys - secondary air pump doesn't sound like it, it had a bit of belt noise from cold, remedied by a new tensioner, but no loud vacuum cleaner noises!

I've seen a few guides on the coolant sensor, would it only be rough on cold starts?

 

[ADAM_84]

all you need to do is let the car warm up, mine does exactly the same whilst the secondary air pump is running wait a minute or so till it stops then drive the car. Think its also to do with the turbo not being up to full operating temperature so it backs the power off to prevent it getting too hot too quickly hence the stutter.

 

[AwesomeSarah]

Faulty coolant temperature sensor could cause that.

Got to agree with that
These are very very common issues
So much so that the old part has been superceeded
059 919 501A is the new part number
A green one instead of the old black one
Sarah

 

[traumapat]

A dirty throttle body can do this too, but id do the temp sender first

 

[MrTurner]

lol - I listened harder this morning when I started it, and had the window down. I have me a vacuum cleaner

First trick, secondary air pump. Second trick, remap.

 

[MrTurner]

Thread with info on blanking:
http://www.seatcupra.net/forums/showthread.php?t=149634&highlight=Secondary+Air+Pump

Thread for info on repairing:
http://uk-mkivs.net/forums/p/141240/940861.aspx#940861

Just in case anyone else stumbles across this thread!

 

[traumapat]

good posts.

 

[cupra-paul]

had a fault the same as this, it was secondary air injection pump.

 

[wurzel]

Lots of different solutions - I had this on my LC to the point where on some cold mornings it sounded like it was running on two cylinders and touching the accelerator caused it to stall. Never had any faults in VAGCOM although eventually a Lambda sensor failed, new sensor fitted and problem went away.

 

[MrTurner]

I replaced the rivits in the pump, but still had the problem. Only when cold still.

Had it remapped yesterday, which found a split hose under the inlet manifold. First start this morning, perfect. So assuming it was a combination of pump and split hose!

 

[Bigbhp18t]

I replaced the rivits in the pump, but still had the problem. Only when cold still.

Had it remapped yesterday, which found a split hose under the inlet manifold. First start this morning, perfect. So assuming it was a combination of pump and split hose!

A combination of things sorted your issue.
A good remap can tidy up the cold start enrichment mapping, PCV pipe fixed and throttle body clean and adapted.

So you have a car that starts ok from cold and kicks out close to 210bhp 240lbft when warm..lol good result.

Ben