Over last few months when fuel is getting Close to 1/3 empty strange rumbling not much power under acceleration, no warning lights. Feels like misfire or misfueling, like it's gonna stall, Mostly all winter been pottering around 20-30mph due to new job, the car does not like my new route to work ( no chance to blast anywhere) also changed to Tesco Momentum 99 December to try save money and this was the start of it, Just filled with Shell Nitro full tank tonight and everything back to normal (for now) though my last visit to top up was also Shell Nitro but it had half the Tesco Momentum in as well. How can it run like normal on a full tank (full boost) but then lose power as the fuel tank goes down) Is fuel getting contaminated? Guess I will know for certain at the end of this fuel top up which is 100% shell Nitro

I suspect fuel pump issue is there any way of putting my garage in right direction as Im there on Friday to sort the rear wiper motor out, I have full tank now and appears to be running fine. Does the fuel pump work harder with less fuel in the tank or is it just the gremlins again..

Edited 26 January, 20224 yr by Kobayashi

You know how much I hate to be 'that guy', the one who provides a much needed reality check:

 

Your fuel pump doesn't care how much liquid is in the tank around it, it'll pump it just the same until that liquid runs out.

 

Your car also doesn't care which brand of fuel you use as long as the octane rating is good.

 

However I think you're right that the new commute doesn't suit the car, so I would reset the ECU and make the car relearn the dynamic map on your new commute to get rid of those bugs you've described but which have no causal connection to the quantity or brand of fuel you're using.

@Kobayashi the 99 Ron min superunleaded should be making no difference really even though it can and has done in the past. The detergents are the difference.  I only used Momentum 99.  Some that Greenergy and Royal Dutch shell bring in can be better than 100 Ron in some areas.      ? So when was the fuel filter replaced?   What remap and mods does your car have now?     If you think a certain petrol is better and no issues with it then just use it.    Shell and Greenergy are partners bringing in the base fuel.    No idea what area you are in but ESSO 99 super unleaded is distributed in most of the UK by Greenergy and where not might have no Ethanol not even 5%.   But then your remapped car should love the stuff.   Best look at those plugs and see if 1 is getting sooted up.   The one that commonly does if pottering about and the car running rich. 

 

Edited 26 January, 20224 yr by roottoot

2 hours ago, sepulchrave said:

 

However I think you're right that the new commute doesn't suit the car, so I would reset the ECU and make the car relearn the dynamic map on your new commute to get rid of those bugs you've described but which have no causal connection to the quantity or brand of fuel you're using.

How do you reset ECU? , the tuning shop I used for years (ADE) is only doing heavy motorsports mods now  (Not general fault finding or service)

I would leave the ECU with remap well alone other than checking the multiplug is well seated.

Inspect or Service the consumables and give the car a bit of a blast new and again.

 

Now it is running fine get the oil hot and then give it a good run and when cooled check how the 4 plugs look.

 

?

Has the Fuel Filter been changed in the time you have had the car?

Edited 26 January, 20224 yr by roottoot

2 hours ago, roottoot said:

@Kobayashi the 99 Ron min superunleaded should be making no difference really even though it can and has done in the past. The detergents are the difference.  I only used Momentum 99.  Some that Greenergy and Royal Dutch shell bring in can be better than 100 Ron in some areas.      ? So when was the fuel filter replaced?   What remap and mods does your car have now?     If you think a certain petrol is better and no issues with it then just use it.    Shell and Greenergy are partners bringing in the base fuel.    No idea what area you are in but ESSO 99 super unleaded is distributed in most of the UK by Greenergy and where not might have no Ethanol not even 5%.   But then your remapped car should love the stuff.   Best look at those plugs and see if 1 is getting sooted up.   The one that commonly does if pottering about and the car running rich. 

 

Gonna go through my old receipts I'm sure the fuel filter was done last year (SEP 21) , car is simply stage 1, not changed plugs in 2 years but hardly any miles done, Im based North West so it's Mainly Shell or Momentum that is above 98.  Its just strange how the stuttering appears with lower fuel in the tank..

No idea about the low fuel tank other than this below,  water in tank.

I never had one low for long and never had a tank less than full when parked up over winter for even a few days.

The E5 is less Hygroscopic than E10 and the Winter Petrol from November to March is less Hygroscopic than the Summer formula. 

 

https://mechanicbase.com/cars/water-in-gas-tank-symptoms/

 

***Any H20 is in the bottom of the tank and not floating on top.***

 

......................

OT.

If the one spark plug gets oiled and soot and then the tip starts to burn off it does not matter how long ago or many miles fitted.

That has caused the death of many a twinchargers.

 

Which plugs are in the car now? 

 

 

You are going to have to possibly drain the tank.  

 

 

 

Edited 26 January, 20224 yr by roottoot

53 minutes ago, roottoot said:

No idea about the low fuel tank other than this below,  water in tank.

I never had one low for long and never had a tank less than full when parked up over winter for even a few days.

The E5 is less Hygroscopic than E10 and the Winter Petrol from November to March is less Hygroscopic than the Summer formula. 

 

https://mechanicbase.com/cars/water-in-gas-tank-symptoms/

 

***Any H20 is in the bottom of the tank and not floating on top.***

 

......................

OT.

If the one spark plug gets oiled and soot and then the tip starts to burn off it does not matter how long ago or many miles fitted.

That has caused the death of many a twinchargers.

 

Which plugs are in the car now? 

 

 

You are going to have to possibly drain the tank.  

 

 

Was Running on Fumes during petrol crisis when it was really cold...that's when I switched to the Momentum Fuel, Plugs if you remember I was only member to burn through a Denso, so it's been platinums NGKs for last 4 years.  Sounds like could be excess water moisture 💦 in tank. A few things to try eliminate then, thanks

I'm talking about resetting the dynamic map, not wiping the ECU!

 

Simply clear codes using a scan tool to do this, I thought you knew what you were talking about@roottoot?

I know when you are talking guff @sepulchrave

 

To clear codes first there have to be codes.

14 minutes ago, roottoot said:

I know when you are talking guff @sepulchrave

 

To clear codes first there have to be codes.

A misfire would be logged in the ecu …. 

Removing the battery for a while would force the car to relearn itself no? 

Just take off the negative terminal off the battery, go in for a cup of tea and put it back on when you're done.

Heard of people "resetting" cars by taking both terminals off and touching them together, then leaving it for a bit.

Don't think it would matter much either way.

 

We've 2 petrol hyundais sitting out in the shed, had them about 4 years. I take them out for runs sometimes, give them a wash etc  but otherwise they just sit. In that 4 years theres never been any issue with water in the fuel. Not new cars either one is 2003 and the others a 2004. Unless you got some seriously bunk petrol I think that won't be your problem.

20 minutes ago, roottoot said:

I know when you are talking guff @sepulchrave

 

To clear codes first there have to be codes.

 

No there don't, it clears the dynamic map even if there are no codes, have you seriously never used VCDS?

 

Guff indeed, you are SUCH a bluffer!

@thomasaspin

Misfires logged will be logged right enough. When enough in a cycle & @Kobayashishould know to be checking for those, he has had enough issues in the past.

 

@sepulchrave 

well i know you bull**** and i have the gear and more than an idea and have read enough fault codes on Twinchargers.

 

I was reading them when @thomasaspin arrived and knew nothing about Mk2 Fabia vRS and needed help with them.

 

Edited 26 January, 20224 yr by roottoot

I would just say if Kobayashi was still using Shell Nitro then it might be a bit old and even watery as it's been (back to) V-Power for quite a time. 😁

 

During or between one of the lockdowns, forget when, my car got a bit of spitting misfire and when I checked fuel delivery quantity and pressure to "the twins" I saw the fuel was slightly milky hazy, topped up the tank (25litres at full) and next full refill with Esso Synergy Supreme+ 99 (E5 labelled 0%).

 

Wind forward to January 2022, another trial fill of Esso Synergy Supreme+ 99 (E5 labelled 0%) car runs really smooth, but I don't have any fancy (or annoying) computers on my car only cable, rods and bits of metal.

 

This afternoon, Mercs and BMW occupying the right hand of the two empty dual-carriageway lanes, even though they were RHD models.  Later an Aldi wanted close inspection of the inside of my tailpipe as I held space from the other cars in the lane, unable to cancel the cruise-control no doubt.  Fortunately I don't have such driver confusing features on my car so once the cars in front pulled over lane I could clear the the plugs and leave the Aldi diminishing in my mirrors.  For as long as I could see him he remained in the outer lane regardless of traffic.  Perhaps as we were travelling west into the sun he felt comfort from seeing the central crash barrier close, he must have forgot his Aldi sunglasses, I have brown eyes.

 

Edited 26 January, 20224 yr by nta16
west

Looked at my old receipts fuel pump never changed in 12 years so that could be failing- fuel filter done every 2 years, got some spare spark plugs as well just in case 1 of them close to failure & will ask if new garage has facility to scan. I was changing plugs from 2016 to 2019 every year averaging 4k miles a year (overkill really)  however car ALWAYS runs better on summer days when oil is almost instantly warm.  Don't know the difference between Shell Nitro and V Power but I've used (Super Shell) for about 9 out of 10 top ups. Maybe it is actually V power and didn't notice the name change...

@KobayashiAre you sure that was the Fuel filter each 2 years and not the Pollen.

 

The Main Dealers Servicing Schedule when it was Minor and Major Servicing used to show the Fuel Filter at each 2nd Major Service with Diesels and some Dealerships did that with Twinchargers. 

http://briskoda.net/forums/topic/464706-fabia-vrs-fuel-filter-replacement-install

 

Edited 26 January, 20224 yr by roottoot

19 minutes ago, Kobayashi said:

Don't know the difference between Shell Nitro and V Power but I've used (Super Shell) for about 9 out of 10 top ups. Maybe it is actually V power and didn't notice the name change...

I was only pulling your leg.  I'm that old I remember Optimax, and I think there was another name before that.

 

 

26 minutes ago, Kobayashi said:

however car ALWAYS runs better on summer days when oil is almost instantly warm. 

The quicker the engine get to operating temp the better, using the oil temp gauge rather than coolant gauge will give you a better idea of when the engine is properly up to temperature.  It also depends on what engine cooling and controls over this.  Once the engine is away from standard there are a lot of considerations.

 

What engine oil do you use (make, model, grade) I'm just curious?

 

(note my 'signature' if you can see it(?))

 

@nta16 

@Kobayashicar was an excessive oil user. 

It got the Oil Spray Jet upgrade done. 

http://briskoda.net/forums/topic/453521-any-pics-of-oil-squirter-location-vrs-14

http://briskoda.net/forums/topic/420740-mk2-fabia-vrs-aka-green-monster

 

The Twincharger oils be it 5w 40 FS so VW502 00 or 5w 30 FS III  VW504 00 507 00 times to get to an indicated 50*oC then to 92 *oC or so has been getting covered since 2010 

with the CAVE and then 2012 with the CTHE.

They are not that slow getting up to heat in warmer weather with the oil for Fixed Servicing or the Variable but in temps nearer freezing it can be as much as 20 miles to get to 90*oC indicated, or in some cases not even get to that. 

 

Average Temps has been covered since the early days and the difference of standard, stage 1 or 2 in times to heat to an efficient operating temp with the different oils is not much different.

You will notice if driving them how the oil too low gets hot rather quickly and the temp comes down slower, that is if paying attention, sadly too many never paid attention to running with low oil and with only a 3.6 litre capacity according to Skoda the oil could be 1.3 litres low and no low oil warning light or message came up.

It could be Low Oil Pressure that showed first.

I used to run 3.9-4. litres of 5w 40 FS.   There were dealership techs that put in that much oil.

 

http://briskoda.net/forums/topic/235544-average-vrs-oil-temperature

http://briskoda.net/forums/topic/282056-at-what-oil-temperature-in-a-vrs-or-other-fabia2-do-you-back-off

 

Edited 27 January, 20224 yr by roottoot

With a standard factory twin-charger I'd want better quality oil than the Dealership use (or charge you for) and I don't know the change intervals but I'd consider more frequently, both more so with a soup'd up car.

 

Perhaps owners have tried top quality oils but I'd hope for better cold flow and more protection cold and when very hot with them as I expect some would make use of the twin-chargers rather than always on economy runs.

 

As well as at least fast-road use oils I'd also expect to keep on top of the whole car servicing and quality air filters (or cleaning) and quality fuel, you certainly can't run these cars on the cheap and expect good performance and reliability.

 

I must admit many years back when I was taken out in a Mk2 at a charity day at Bruntingthorpe I thought the young driver might be pulling my leg when he said it was a 1.4 with turbo and supercharger but I was very impressed with the performance.

 

On my phone so can't see signatures or tag but Oil has always been Castrol Edge & that only gets changed every service now. The 5 Skoda fixes did solve the oil issue, Most of my other issues always appear in winter, very short journeys car running cold. Fuel filter has been changed 5 times in 10 years, the tuning shop (which is not available now) and my local garage have always done good work for me. Will see what they come up with ie Plug condition, Fuel Pump / Filter. Surprised the car has lasted this long TBH 

@nta16. People tried race oils and the best they could buy.  None of that mattered for road use.  5w 40 FS was perfect.    The Long Life Oil and Super unleaded which is the recommended petrol for Twinchargers could be an issue.   Bore wash was an issue.  The engines did not require Long Life oil and more detergents in the petrol.   If you are interested in some history then there is pinned threads up top.  Including links to Lucifers Guides part one and 2 and the oil thread with many many pages. 

4 minutes ago, Kobayashi said:

On my phone so can't see signatures or tag

Signature (tag?) -

Please note - I am not a mechanic or expert in anything.

Cheers, Nigel.

www.sportingbears.co.uk

 

 

5 minutes ago, Kobayashi said:

Oil has always been Castrol Edge

That's what (is supposed, Professional version no doubt) to go into my wife's standard Mk3.

 

 

47 minutes ago, Kobayashi said:

very short journeys car running cold

That'll be a problem always. 

 

I like this local oil blender, this might help a little (or you could ask Millers Oils about their other motorsport oils that might be suitable and can be used for road use)  - Millers Oils EE Performance C3 5w-30 Fully Synthetic Engine Oil - https://www.opieoils.co.uk/p-74218-millers-oils-ee-performance-c3-5w-30-fully-synthetic-engine-oil.aspx

 

1 hour ago, roottoot said:

@nta16. People tried race oils and the best they could buy.  None of that mattered for road use.  5w 40 FS was perfect.    The Long Life Oil and Super unleaded which is the recommended petrol for Twinchargers could be an issue.   Bore wash was an issue.  The engines did not require Long Life oil and more detergents in the petrol.   If you are interested in some history then there is pinned threads up top.  Including links to Lucifers Guides part one and 2 and the oil thread with many many pages. 

Sorry I got called away I'll have a look later, thank you.  I was think of the faster warm up at cold but also the longer lasting wider margins of protection.  You don't want out and out race oils, I was thinking road use type completion (drive to, on and away from the track with the same oil).