Rough acceleration when cold.

[FluffyEyeball]

Hi, my vRS TSI has in the past few months started this, it only happens when the engine is cold soon after starting. When accelerating through (usually) either 1st, 2nd, or 3rd gear, I will feel a brief hesitation in the acceleration. Almost like a 'cough' or very brief misfire? It happens usually under normal light-moderate acceleration. It isn't all the time, sometimes it will be perfectly normal, other times it will do it a few times that journey. Outside air temperature seems to make no difference to the frequency or severity.

 

The spark plugs look good (changed within past two years during service), coils are not contaminated, and the car has never stored any fault codes that could be attributed to this. 

 

Any ideas? Thanks muchly

[Tilt]

Fuel filter due a change????

[FluffyEyeball]

I think they have a long life fuel filter on the 2.0 TSI's

[SuperbTWM]

is it a high mileage car?

[GenOtmin]

25 minutes ago, FluffyEyeball said:

I think they have a long life fuel filter on the 2.0 TSI's

Still would have a look at it.

[Ootohere]

A Long Life fuel filter that is not Life Long.

 

The Manufacturers Guidelines as there is no Service Schedule from the Manufacturers is at the 2nd Major Service with a TDI for a Fuel Filter change.

So that will be at under 40,000 miles / 48 months.

[Tilt]

@Skoffski Op has a TSi. 

Edited 28 April, 2019 by Tilt

[Ootohere]

@Tilt

 

I read that.  Head for thinking, feet for dancing.

 

The point being Long Life filter.   Not Life Long, or even that Long Life.

 

VW / Skoda Fixed price Servicing on 3-10 Year old TDI cars have Fuel Filter as a Major Service Item, but with TSI's have Spark Plugs, 

no mention of Fuel Filter.

 

Master Techs in the know change Fuel Filters with a TSI.

Edited 28 April, 2019 by Skoffski

[FluffyEyeball]

On 28/04/2019 at 11:10, SuperbTWM said:

is it a high mileage car?

 

Not really no, late 2014 car and it's just done 50000 miles. 

 

@Skoffski  @GenOtmin  I did consider the filter, but the fuel filter on the 2.0 TSI is integrated within the fuel pump and can't be got at or replaced individually. 

[Ootohere]

Best get the spark plugs out and check the gap.

While out replace them.

I take it the Air Filter is clean and fresh.

 

Do you use 95 ron unleaded and have you tried 97 ron Super Unleaded from BP, ESSO, Sainsbury etc or 99 ron Tesco Momentum 99.  Costco Super Unleaded or Shell V-Power Nitro+

to see if any difference?

[FluffyEyeball]

40 minutes ago, Skoffski said:

Best get the spark plugs out and check the gap.

While out replace them.

I take it the Air Filter is clean and fresh.

 

Do you use 95 ron unleaded and have you tried 97 ron Super Unleaded from BP, ESSO, Sainsbury etc or 99 ron Tesco Momentum 99.  Costco Super Unleaded or Shell V-Power Nitro+

to see if any difference?

 

Sparks were out a few months ago (after this started) for another reason, all looked good with correct gap.

Air filter is less than 12 months old, although I haven't looked at it recently but I will do this, thank you.

I use RON 99 fuel all the time. Used to be from Costco, but they've changed to RON 97 now, so I use Tesco as it's cheaper than Shell. It would only ever get less than RON 99 as a last resort if I was desperate, and only enough to get me to the next fuel station with 99. 

[SuperbTWM]

7 hours ago, FluffyEyeball said:

 

Not really no, late 2014 car and it's just done 50000 miles. 

 

@Skoffski  @GenOtmin  I did consider the filter, but the fuel filter on the 2.0 TSI is integrated within the fuel pump and can't be got at or replaced individually. 

 

It will have a filter other than the one in the fuel pump.

 

i'm pretty sure misfires when cold is a symptom of the valves getting gummed up with carbon but at 50K it seems unlikely unless it has been driven very gently all its life

Edited 29 April, 2019 by SuperbTWM

[FluffyEyeball]

22 minutes ago, SuperbTWM said:

 

It will have a filter other than the one in the fuel pump.

 

i'm pretty sure misfires when cold is a symptom of the valves getting gummed up with carbon but at 50K it seems unlikely unless it has been driven very gently all its life

 

Skoda workshop manual doesn't list any other filter, and I can't find evidence of one.

 

I'd not thought of the valves...I'll look into that thanks. It's not been driven very gently though, a mixture of normal and fairly hard. 

[cheezemonkhai]

At 50k I would do the fuel filter. It is a 60k job anyway.

 

fwiw did you damage to coils at all when checking the sparks? Small splits can degrade them and they are, from what I hear, a pig to remove without damage.

[Rybu79]

So has the petrol got a fuel filter? 

 

Im confused. 

[FluffyEyeball]

4 hours ago, Rybu79 said:

So has the petrol got a fuel filter? 

 

Im confused. 

 

Yes, it has a fuel filter but it is incorporated within the fuel pump itself and cannot be changed separately, it's designed to last the life of the pump.

[Rybu79]

Thanks.