Hi first time posting and looking for some help please. 2014 Octavia 1.6 Diesal having trouble after engine starts car seem low in power and chuggs along until what seems fuel kicks in and then off shes goes. Any ideas

A couple of pointers:

 

1) Are there any errors showing on the car dash?

2) Does this happen from cold or also when hot?

3) When was the last time the diesel filter was changed over?

4) Service History - when was the last service and what was done at that service?

5) Is your engine a EURO5 or EURO6 engine?

6) What fuel do you run it off (supermarket or otherwise)?

7) What kind of mileage do you do - long runs (over 10 miles) or short journeys (under 10 miles).

 

Thanks for your reply 

 

No warning lights

Mostly first thing in the morning 

Not sure about diesel filter (will find out)

Just serviced 

Not sure what Euro 5 or 6 is

Fuel. Never from a supermarket 

Always long journeys as I'm outside the city

The most obvious issue sounds like its an intermittent (and failing) Fuel pump.  The key thing is getting your car to a person with a VCDS system.  They can 'read' your car and its errors.  Intermittent errors don't always show on the dashboard.  The reason why I asked whether your car was a Euro 5 or Euro 6 engine - was that VW Group recalled all Euro5 engines, changed the jets and put new firmware onto the cars (for Dieselgate).  This modification caused performance issues.  The other issue around the fuel diesel fuel filter was whether it changed correctly.  Not topping up the filter bowl and not re-priming the pump may also cause fuel starvation.  However, my guess is going to be a failing pump - which will show up on the CANBUS network.

 

Failing a diagnostic visit to your local Skoda dealer or your local VW specialist (try https://www.vassmotorworks.ie/about-vass-motorworks-garage-car-servicing-repair/) or a visit to Galway or Dublin to meet up with a registered VCDS owner - https://www.google.com/maps/d/viewer?msa=0&mid=1Td73_uUUqscV3nRm5br_o89PmBU&ll=52.972709670174076%2C-7.903861277928392&z=8 to read the car diagnostics.  You will probably get an error code - which we can then all tell you what the problem is reporting.

 

Edited 29 December, 20205 yr by varaderoguy

What jets are you saying were changed during the recall?

 

What does a stored fault code for a fuel pump failure have to do with the Canbus network?

 

I had not realised that EU5 diesel engines used a carburettor, you learn something every day, last week it was that the ECU detects what octane fuel is in the tank and adjusts the mixture to suit.

 

The week before it was that the canbus network monitors the lighting & signalling bulbs & there was me thinking that it was simply a means of communicating data & commands between modules.

 

 

6 minutes ago, J.R. said:

What jets are you saying were changed during the recall?

 

What does a stored fault code for a fuel pump failure have to do with the Canbus network?

 

I had not realised that EU5 diesel engines used a carburettor, you learn something every day, last week it was that the ECU detects what octane fuel is in the tank and adjusts the mixture to suit.

 

The week before it was that the canbus network monitors the lighting & signalling bulbs & there was me thinking that it was simply a means of communicating data & commands between modules.

 

 

@J.R. - apologies, but I didn't say any of the above.  All I mentioned was - was the car a Euro5 or 6 engined beast (modifications caused issues) - and fault codes are stored in the *ECU*.  The CANBUS network is essentially a two-wire ethernet - see the following: http://www.mindsensors.com/content/86-can-and-its-topology . As well as lighting and providing power, data traversing down those said same wires.  

27 minutes ago, varaderoguy said:

The most obvious issue sounds like its an intermittent (and failing) Fuel pump.  The key thing is getting your car to a person with a VCDS system.  They can 'read' your car and its errors.  Intermittent errors don't always show on the dashboard.  The reason why I asked whether your car was a Euro 5 or Euro 6 engine - was that VW Group recalled all Euro5 engines, changed the jets and put new firmware onto the cars (for Dieselgate).  This modification caused performance issues.  The other issue around the fuel diesel fuel filter was whether it changed correctly.  Not topping up the filter bowl and not re-priming the pump may also cause fuel starvation.  However, my guess is going to be a failing pump - which will show up on the CANBUS network.

 

Failing a diagnostic visit to your local Skoda dealer or your local VW specialist (try https://www.vassmotorworks.ie/about-vass-motorworks-garage-car-servicing-repair/) or a visit to Galway or Dublin to meet up with a registered VCDS owner - https://www.google.com/maps/d/viewer?msa=0&mid=1Td73_uUUqscV3nRm5br_o89PmBU&ll=52.972709670174076%2C-7.903861277928392&z=8 to read the car diagnostics.  You will probably get an error code - which we can then all tell you what the problem is reporting.

 

Thanks for you reply

7 minutes ago, varaderoguy said:

@J.R. - apologies, but I didn't say any of the above.

 

Was it someone else then that said:

 

VW Group recalled all Euro5 engines, changed the jets and put new firmware onto the cars (for Dieselgate).

 

my guess is going to be a failing pump - which will show up on the CANBUS network.

 

The latter I understood what you meant and I was being a bit naughty so I apologise, for the former I would still like to know if any components were changed (jets may simply be the wrong terminology) because I am looking in detail at how I can either reverse or remove the effects of the "emissions fix" that had previously been done to my vehicle, I had thought it was a software update and not a physical change.

2 minutes ago, J.R. said:

I had thought it was a software update and not a physical change.

Nope - bigger jets and a firmware change on the Euro5; but we are hijacking this thread unnecessarily.

Please tell me what jets you are talking about, it is relevant.

Maybe he's refering to the "flow transformer" device thats fitted to reduce swirl.

 

Quote

2.0-litre models are given a simple software update, whereas the 1.6-litre cars receive a hardware upgrade in the form of a ‘flow transformer’, which according to VW “calms the swirled air flow in front of the air mass sensor and will thus decisively improve the measuring accuracy of the air mass sensor.”

 

Possibly, it could be a 2nd language thing, "jets" being plural would indicate something like the injectors.

 

Is there a difference between a "software change" as I had thought and a "firmware change" as it was corrected to?

1.6 engines had the airflow thingy, 2.0s didn't - no hardware changes at all. Software/firmware same thing in this context, I think.