Hello all!

Need some help once again 🫠. Its got pretty clear that my 98 Felicia is running quite poorly on fuel (around 260 miles per tank of 99 octane). I’ve had a research and was hoping maybe some more insight could be given? I’ve had a play around with the coolant temperature sensor and that doesn’t seem to be the issue (reads fine, struggles to start without it at running temp) so curious if anyone else knows what it could be? I’m not sure if it’s linked but it’s worth adding context: when fueling the car, the petrol pump stops if i’m holding the trigger down, meaning I have to spend about 15 minutes fueling the car! Any help would be appreciated thank you very much! It’ll be having an oil change and spark plugs service soon so I’ll see if that has any effect too!

Do you have VCDS? Can you give us a graph of your lambda values please?

If we rule out the lambda sensor its either the injectors or the fuel delivery. Low pump pressure will cause increased fuel consumption in closed loop operating mode

You could check the lambda ("oxygen") sensor with a multimeter, plenty of YouTube videos on this, some good, some not-so-good.

20 minutes ago, Luck said:

I’m not sure if it’s linked but it’s worth adding context: when fueling the car, the petrol pump stops if i’m holding the trigger down, meaning I have to spend about 15 minutes fueling the car!

Could it be that you're ramming the nozzle in too far and getting splashback or fumes, I can't remember now if the 1998 UK fuel cap entry pipes were restricted in size like modern petrol ones.

How clean and clear is the area around the filler if it's covered in debris then clean it all out and check any small hole is open and not stuff. Do you have any sort of EVAC system?

Do you normally fill the tank and know the actual capacity of your tank when full rather than what the book says?

For a reasonably accurate mpg you need to fill the tank and then record the mileage and litres needed to refill to full again at next fill and divide one into other, after dividing litres by 4.54 for mpg. 260 miles is good for a (actual) 6 (UK) gallon tank but not so good for a (actual) 10 (UK) gallon tank.

36 minutes ago, Luck said:

It’ll be having an oil change and spark plugs service soon so I’ll see if that has any effect too!

Don't forget about the air filter and air filter box and pipes. Service of the whole car is best but if this is just to help sort the fuel issue fine, but bear in mind the engine is not the most important component, system or part of a vehicle.

21 minutes ago, nta16 said:

Don't forget about the air filter and air filter box and pipes. Service of the whole car is best but if this is just to help sort the fuel issue fine, but bear in mind the engine is not the most important component, system or part of a vehicle.

Yeah do need that looked at gonna see if theres anything else that can be done alongside the rest of it. Its a 42 litre tank so around 11 gallons I think (from google). Which surely is not correct! With the fuel thing i’ve tried it everywhere and it always catches and stops fuel (like when you’re overfilling it). Currently I just put around 40L in as I run it to the last quarter. I don’t have anything to read any oxygen readings etc though, is there any other parts you suggest replacing / servicing? Its being taken to a nearby garage tomorrow as I’ve not got much spare time to look into it currently. Thank you very much for the help 🙂

Tank and other capacities tend to be nominal (not exactly spot on) and relate to something when it's new and no or little use not 27 years of use and possibly abuse and neglect. A metal fuel tank can be dented reducing whatever it's real capacity was anyway, plastic liner sucked in.

42 litres can't be 11 UK gallons as one gallon is 4.546 litres as I put for calculating mpg. You have calculated to US gallons not UK gallons and despite what some Americans may think they don't yet own the UK so we are free to use UK and European metric measurement systems.

42 litres is 9.24 (my rounding of figure) UK gallons. But you tank may not hold 42 litres, it may hold less or even perhaps more but that is more doubtful. Never try to overfill the tank and filler pipe.

If you run to a 40 litres fill then you are well into the bottom of the last quarter (10.5 litres nominally) so the over-complicated VW fuel gauge may be inaccurate (at that level of fill at least) and/or you might be overfilling the tank and filler pipe.

Despite VW making the fuel gauge unnecessarily complicated, especially for 1998, you should still use it as a "gauge" rather than an "accurate", that is don't fully trust the swing needle position or any figures (same with figures and "facts" you get from computers) always verify the accuracy or approximate accuracy. The fuel gauge in my wife's 2016 VWŠkoda has never been fully accurate.

The most reasonably accurate system to check mpg on your pick-up is to follow the procedure I put before but you do need to have a reasonable and consistent idea of when your tank is full, normally this is when the petrol station pump clicks off which you can't achieve yet, again I put my ideas of how to possibly achieve this in my last post.

11 hours ago, Luck said:

I don’t have anything to read any oxygen readings etc though, is there any other parts you suggest replacing / servicing? Its being taken to a nearby garage tomorrow as I’ve not got much spare time to look into it currently. Thank you very much for the help 🙂

Thefeliciahacker and others here know far more about Felicias and mechanics and electrics than I do but a simple multimeter can tell you if the lambda is reasonably working. IF it needs replacing then it can be important to get the exactly correct sensor for your Felicia to fully work properly generic replacement may not work as fully as they should, posts on such are on here. bear this in mind and tell the garage.

Thank you for the thanks it is very much appreciated but Thefeliciahacker and others will be able to help you more but as I've lived in the UK (England) all my life I understand some things more about conditions in the UK than those that don't live in the UK and as I'm not very technical I can understand things more from a "classic" car beginners' point of view and for 30+ years I ran 20-50 year old cars as daily runners so have some knowledge and decades of experience (but very little with VWs, but we did own four Škodas from 1985 to early 1990s when they were new cars, VW had just begun to take over by then and quality initially dropped!! Škoda Dealerships were much, much better then than later and now, they had to be to keep their (loyal) Škoda customers as the other large manufacturers of the time got the media to make the Škoda brand a laughing stock in the UK because it threaten their car pricing and lack of warranties.

Good luck.

15 hours ago, Luck said:

is running quite poorly on fuel (around 260 miles per tank of 99 octane).

That's 10.4 ltr/ 100 Km which is reasonable in hard city traffic. This is your average fuel consumption?

No need for 99 RON gasoline in an every day cool driving style.

15 hours ago, Luck said:

meaning I have to spend about 15 minutes fueling the car!

That's impossible, the hole beneath the cap is free from debris etc?

Yeah it’s my standard consumption, I do a bit of long distance driving and running about to the shops etc but i’m on the outskirts of a city so the traffic is never too terrible! And yes free of all debris and everything, I will try to get some pics once the car is back. In regards to 99 RON i’ve had a few people suggest it and I believe its even suggested by the UK government but it’s hard to say as I’ve never been too sure

10 minutes ago, Luck said:

In regards to 99 RON i’ve had a few people suggest it and I believe its even suggested by the UK government but it’s hard to say as I’ve never been too sure

The information is freely available to check what these people (or anyone else including these often inaccurate AI systems).

The following information is in other post(s) on here too. From the UK Government website. -

"Important E10 information

The E10 petrol check has been created by the Department for Transport (DfT) using information supplied by the European Automobile Manufacturers' Association and European Association of Motorcycle Manufacturers.

The information is subject to change and we cannot guarantee its accuracy. If your vehicle is fitted with replacement parts this will also affect its accuracy.

DfT and its partners will not be liable for any damage to your vehicle as a result of you using this service.

It's your responsibility to make sure you use the right fuel for your vehicle.

Continue"

"Škoda

E10 petrol is cleared for use in all ŠKODA vehicles with petrol engines with the following exceptions:

* Felicia 1.3 litre OHV (40kw and 50kW) engines in the production years 1994 to 2001

* Other ŠKODA models using the 1.3 litre OHV engines produced prior to 1994.

NOTE: If your vehicle is listed above you should continue to use E5 petrol. If you are unsure please contact your local Škoda dealer."

https://check-vehicle-compatibility-e10-petrol.service.gov.uk/en

The petrols in the UK are either up to 10% or up to 5%, the up to 5% are also higher octane but also container a higher cleaning additive package - all three elements are helpful to the older engine designs and builds and UK winters are now mild, wet and damp.

petrol.pdf

ETA: the potty POTUS has signed us up in the UK to help with subsidise some of their farms and probably the up to 5% and up to 10% fuels will get nearer to their top figures of ethanol, that is 10 and 5%.

Edited 23 December, 202523 Dec by nta16
ETA:

@Luck Handy if you say how many liters of 99 octane E5 you use in the 260 miles? Is it 99 From Shell . Tesco or ESSO or maybe 97 ron from the others selling E5. Just curious but is your engine fine to run on 95 ron E10?

3 hours ago, Luck said:

Yeah it’s my standard consumption, I do a bit of long distance driving and running about to the shops etc but i’m on the outskirts of a city so the traffic is never too terrible!

These are some examples from my MPG.

https://www.briskoda.net/forums/topic/512393-cooling-system-problem-again-in-my-felicia/page/3/#findComment-5946337

https://www.briskoda.net/forums/topic/512393-cooling-system-problem-again-in-my-felicia/page/3/#findComment-5945839

https://www.briskoda.net/forums/topic/512393-cooling-system-problem-again-in-my-felicia/page/5/#findComment-5955158

https://www.briskoda.net/forums/topic/512393-cooling-system-problem-again-in-my-felicia/page/6/#findComment-5959014

https://www.briskoda.net/forums/topic/512393-cooling-system-problem-again-in-my-felicia/page/6/#findComment-5959514

https://www.briskoda.net/forums/topic/512393-cooling-system-problem-again-in-my-felicia/page/6/#findComment-5960293

In the past i had even 14,7 / 100 km or 19.22 British MPG which was a terrible result and took me at least a year to find the solution and was not only 1, was a heaps of faults (small or even less) which all together made my Felicia spend more fuel than it should be.

Issue seems to have been found, a misfire, so need a new coilpack 😵‍💫So time to tuck it away till new years, thank you everyone for your help & suggestions! Would have preferred it to be a sensor though..

Often forgotten or ignored If your HT leads are very old also consider replacing them as they're not expensive for a set - but don't buy inexpensive Chinese, or elsewhere, crap made ones.

In my experience you can get an average fuel consumption of 7.7L/100km in reality I can get it down to 6.3L/100km but with my failing fuel pump that drops pressure you can't get anything better.

1 hour ago, Luck said:

Issue seems to have been found, a misfire, so need a new coilpack

Buy the orinigal,is CHAMPION as the spark plugs.

7.7L/100km = 37 m,pg (UK,, imperial)

6.3L/100km = 45 mpg (UK, imperial)

10.4 ltr/ 100 Km = 27 mpg (UK, imperial)

https://www.omnicalculator.com/conversion/fuel-economy-converter

On 23/12/2025 at 10:54, nta16 said:

If you run to a 40 litres fill then you are well into the bottom of the last quarter (10.5 litres nominally) so the over-complicated VW fuel gauge may be inaccurate

You know, it's really tiring to read these comments. We get it, you hate VW, no need to mention it in every post, especially when the part in question has nothing to do with VW. The float and entire instrument panel is development of Favorit made in CZ, not a VW part.

If you don't have anything nice to say, then don't say anything.

Edited 31 December, 202531 Dec by Papez

42 minutes ago, Papez said:

You know, it's really tiring to read these comments. We get it, you hate VW,

1 hour ago, Papez said:

no need to mention it in every post,

, especially when the part in question has nothing to do with VW. The float and entire instrument panel is development of Favorit made in CZ, not a VW part.

If you don't have anything nice to say, then don't say anything.

I'm sorry I thought it had been explained to me the complicated way the fuel gauge reading mech is (possibly by Thefelieciahacker) and it was you that pointed out and reminded me of when VW took over so by 2000 VW were years into ownership and running things so the cars were VW Škoda badged.

1 hour ago, Papez said:

no need to mention it in every post,

I expect you have been told a million times about exaggerating. 😁

Lots of comments and advice are very repetitive to those on the forums for a long time but for those new(er) to the site they can be new. I don't hate VW but I certainly have some loathing for company given my knowledge and experience of them and I feel I can offer alternative and balance to the fan boy attitude of some and make my attitude clear so there's no mistake for those that haven't seen too many of my posts previously, posters and viewers only.

I give VW and their products credit when and where it is due and will even defend the product in those cases in posts on this site.

I've also tried to help with this issue, calculating MPG (as this is a UK car) (and considering Google and computer answers) for Luck and other viewers past, present and future.

BUT - I take your point and will lay off a bit and might consider using 'VWŠkoda' more here (as I do on this Briskoda's other forums).

It is not always correct but it is cute when said like this -

Edited 31 December, 202531 Dec by nta16

This is for Felicia

Some people sell the same as VW Genuine part

eBay

Vag Caddy Mk2 Pickup 1997 2001 Fuel Gauge Genuine 6U09190...

Part Number: 6U0919045C. Caddy Mk2 Pickup 1997 - 2001. ONLY GENUINE PARTS. of your car and we will check if the part fits specifically your vehicle. Used Car Parts. A TTENTION !! Service Kits.

The cluster gauge is from VDO a German company (Vereinigte DEUTA - OTA).

The Favorit had a different design cluster,the maker was PAL a Cz company.

https://pal-wiping-systems.com/produkty/

2 hours ago, nta16 said:

I'm sorry I thought it had been explained to me the complicated way the fuel gauge reading mech is

It's not, it's same as in Favorit. It just have some simple analog circuitry (that could be made by Tesla in 80's, so nothing overcomplicated for 1998) to slow down the needle when the fuel sloshes around. The inaccuracies were same as on older Skoda's - usually caused by increased resistance on any of the connection between the float and needle.

Byltw, by the time of Felicia, VW already had fully digital instrument clusters. Meanwhile, Felicia still had mechanical speedometer in 2001.

2 hours ago, nta16 said:

it was you that pointed out and reminded me of when VW took over so by 2000 VW were years into ownership and running things so the cars were VW Škoda badged

I also pointed out several times that Felicia is basically a facelifted Favorit. Most of the car was built in the same way as the Favorit and the few VW sytems like ABS or ECU weren't as integrated into electrical and mechanical systems as they were on newer cars. First Skoda build on VW platform was MK1 Octavia, which is not discussed on this subforum, so there's no need to mention VW.

2 hours ago, nta16 said:

BUT - I take your point and will lay off a bit and might consider using 'VWŠkoda' more here (as I do on this Briskoda's other forums).

The last sentence applies to this as well.

2 hours ago, nta16 said:

I expect you have been told a million times about exaggerating. 😁

At this point, I don't even feel exaggerating. I've just seen too many kicks into VW in Felicia topics and this one was entirely unnecessary.

10 minutes ago, D.FYLAKTOS said:

The cluster gauge is from VDO a German company (Vereinigte DEUTA - OTA).

It's made by VDO Instruments Adršpach Česká republika. Many "German branded" components for Felicia were actually made in Czech Republic. Usually by companies that got bought by larger foreign companies.

But really, nothing above has anything to do with increased fuel consumption... Maybe the only thing worth checking would be fuel tank venting, that could cause issues with filling, but I doubt it could cause high consumption. That could be lambda probe (or exhaust leak around it), vacuum leak, or fuel pressure issues, as mentioned above.

Edited 31 December, 202531 Dec by Papez

26 minutes ago, Papez said:

That could be lambda probe (or exhaust leak around it), vacuum leak, or fuel pressure issues, as mentioned above.

But @Luck didn't mention yet anything about a scanner tool,does not know if there are any codes.

He found that the culprit was the DIS coilpack but he didn't said how.

The local repair-shop has not a VCDS or any scanner to run a check?

1 hour ago, Papez said:

to slow down the needle when the fuel sloshes around

and compensate to an extent for the non-linear volume increase in a geometrically complex fuel tank

33 minutes ago, D.FYLAKTOS said:

He found that the culprit was the DIS coilpack but he didn't said how.

I don't think that's the culprit. That would be surely visible on spark plugs - and he said nothing about how the old ones look. Also, I had faulty coils on my car - you notice something's wrong long before you get to the petrol station.

35 minutes ago, D.FYLAKTOS said:

does not know if there are any codes.

These engines only throw codes when something's really wrong. They need to be checked throughougly on the diagnostics and even extra tools to make sure everything works correctly.

1 hour ago, Papez said:

Maybe the only thing worth checking would be fuel tank venting, that could cause issues with filling, but I doubt it could cause high consumption. That could be lambda probe (or exhaust leak around it), vacuum leak, or fuel pressure issues, as mentioned above.

I agree, purge valve usually causes codes (EVAP) and it is properly monitored by the ecu.

Injectors may also be the culprit, the lambda sensor though, tends to be my gut feeling, also it's worth adding that misfires will very often register under lambda errors as system too rich and they will be stored not pending.

2 minutes ago, Papez said:

That would be surely visible on spark plugs - and he said nothing about how the old ones look. Also, I had faulty coils on my car - you notice something's wrong long before you get to the petrol station.

If you use CHAMPION coil pack btw you can measure its resistance to see how deep into it's life is, I say new old stock champion as only these coilpacks used the integrated coil driver VB 921.

I will post the measurements