7 minutes ago, Thefeliciahacker said:

Its the fuel pump priming it will run for 3sec to build pressure you will hear the relay click off, its a slight buzz under the rear seats.

I know exactly what is happening it is running so rich that is causing a flameout condition meaning it wets the sparkplugs, and it sounds like this, I bet the temp gauge doesn't budge If you want take a 2k resistor and plug it into the socket of the ect fooling the ECU like its around 20C and it will start instantly and you can use a 10k pot in rheostat config (so using an outer and a middle leg) to fool the gauge and check (but be carefull to not drop the resistance of the gauge to zero as you gonna fry it, add a series resistor of 330Ω if you are afraid

That sounds something like what a competent mechanic would do (I don't even have any resistors, so that's a bit futile 🙂). we'll just get a new ECT sensor and fit that instead, and start better diagnosing and problem solving on other issues that we'll find on the car. 👍

In old terms it's flooded cos the car's 'puter ain't not getting told right.

In the videos you put up the exhaust smoke didn't show any bad over-fuelling.

3 minutes ago, Thefeliciahacker said:

If the injectors arent stuck open then yes

And there we have why you question 99% or 100% of what. The ECT may not be 99% or 100% responsible for failure to start, other factors and elements may also be in the mix for the failure. That is not to say the that 99% or 100% might not be faulty and possibly responsible for non-start when all else is ruled out.

Just now, TonyW1967 said:

a new ECT sensor and fit that instead, and start better diagnosing and problem

before you buy please check the coilpack its a 10 minute job just to iron it out,

1 minute ago, nta16 said:

And there we have why you question 99% or 100% of what. The ECT may not be 99% or 100% responsible for failure to start, other factors and elements may also be in the mix for the failure. That is not to say the that 99% or 100% might not be faulty and possibly responsible for non-start when all else is ruled out.

Yeah the running video seems weird and doesnt align with ECT but then again the start video is textbook ect

1 minute ago, nta16 said:

In the videos you put up the exhaust smoke didn't show any bad over-fuelling.

If you cannot burn it you will not see black smoke

1 minute ago, Thefeliciahacker said:

Yeah the running video seems weird and doesnt align with ECT but then again the start video is textbook ect

If you cannot burn it you will not see black smoke

Only saw white/grey smoke - unless at high revs - no smoke at all then.

Edited 7 January7 Jan by TonyW1967

Just now, TonyW1967 said:

Only saw white/grey smoke - unless at high revs - no smoke at all then.

Check the coilpack please. Easy enough to do, there is the possibility of a loose solder joint or the planned obsolescence flyback diodes failing, shorting one pair of cylinders and not being able to fire

2x5mm allen and 10 minutes

You can perform an electrical check in situ by measuring with a multimeter as such

Edited 7 January7 Jan by Thefeliciahacker

On 06/01/2026 at 14:36, Thefeliciahacker said:

yep we can, but its not a guarantee someone will have not installed the sensor rotated, the ref should be with the plug key

Sorry, the sensor itself can only go in one way, so I assume you refer to when you connect the female cap to the sensor body? If so, how to know the right way round, when connecting the cap?

5 minutes ago, Thefeliciahacker said:

Check the coilpack please. Easy enough to do, there is the possibility of a loose solder joint or the planned obsolescence flyback diodes failing, shorting one pair of cylinders and not being able to fire

2x5mm allen and 10 minutes

You can perform an electrical check in situ by measuring with a multimeter as such

Will do

Just now, TonyW1967 said:

Sorry, the sensor itself can only go in one way, so I assume you refer to when you connect the female cap to the sensor body? If so, how to know the right way round, when connecting the cap?

No, @D.FYLAKTOS said we should orinent ourselves in reference to the firewall, which is subject to the clocking of the sensor itself, since its held by a D clip and an oring it can be rotated 360deg meaning that pins 1-3 and 2-4 will not always be on the same side, infact the can be in any direction, that is why we have to reference ourselves from the key that is used for aliging the plug to the sensor.

1 minute ago, Thefeliciahacker said:

No, @D.FYLAKTOS said we should orinent ourselves in reference to the firewall, which is subject to the clocking of the sensor itself, since its held by a D clip and an oring it can be rotated 360deg meaning that pins 1-3 and 2-4 will not always be on the same side, infact the can be in any direction, that is why we have to reference ourselves from the key that is used for aliging the plug to the sensor.

So there is an alignment channel on the cap, that aligns with an alignment key on the sensor body connection? Then how could it be fitted incorrectly?

24 minutes ago, TonyW1967 said:

but his experienced garage mechanic friend (the one who gave him the car) is coming around tomorrow with his diagnostic kit,

As with the others here part of the experienced garage mechanic friend's diagnostic kit will be his education, training and experience.

But also probably a multimeter as well as his human senses. You and your son won't have the friend's education, training and experience butt you can both gain some education and experience from the ownership and running of the Felicia and you have your human senses, you can look, listen, smell, taste (careful with that) and feel things on and about the car.

It doesn't seem you get much out of these cars with the, over relied on now, scan tools but even with the newer cars a human can tell there's something wrong even when the computers don't throw up error codes. (parameters tend to be very wide on some things).

2 minutes ago, TonyW1967 said:

So there is an alignment channel on the cap, that aligns with an alignment key on the sensor body connection? Then how could it be fitted incorrectly?

Its just wires, they can be rotated and the next guy will just twist the plug to align it with the socket I aint saying that it is connected incorrectly as you are right this cannot happen I am saying you have to pay attention to which set of actuall pins you are measuring

Edited 7 January7 Jan by Thefeliciahacker

13 minutes ago, Thefeliciahacker said:

Check the coilpack please.

Also as suggested previously by another member check all connections and for damp and corrosion/crud - whether part of or contributing to this issue or not. Anything you touch on an old car new to you inspect, clean and if required lubricate as you go along even if you can't repair or replace it at that stage. As note now an accumulation of things can contribute to cause more and more involved issues and solutions so eliminate as much as you can from present and future issues as you go along. Don't expect your mechanic friend to do this he's just concerned with the issue he's been called out to, don't think because he looked at it and/or touched it that it must be good or sorted.

41 minutes ago, TonyW1967 said:

we'll just get a new ECT sensor and fit that instead, and start better diagnosing and problem solving on other issues that we'll find on the car.

Be aware of D's advice don't buy a cheap one, an incorrect or p1ss-poorly modern made part could introduce more problems than it solves, if it solves anything. I'm not against spending small amounts of money on parts to save unwanted hassle but it does need to give some resolve or you're just delaying the issue.

Sometimes/often keeping or refurbishing an old or original can be better than replacing with a modern made part even if the modern made parts fits and works.

Once a car is driveable things tend to be a lot easier to sort, and things improve more as the car is used more and with more regular frequency over reasonable distance journeys where the engine oil gets fully warmed and so do the other systems and they are exercised more.

As with the exhaust smoke perhaps, which if not part of your current issue, could perhaps be bettered with car use, servicing and maintenance and the use of petrols with lower ethanol and higher cleaning additive packages.

Without knowing the history of the car you can think it'll be a quick wash 'n' polish and the imagined obligatory change of engine oil and it's off to the next owner with a profit, all those "classic" car turn-around shows are very, very, economical with the truth..

Edited 7 January7 Jan by nta16

It sounds like it's running on two, or even one cylinder. It may be the ignition module, mine was more sensitive to moisture, probably because of cracked insulation. But it can also be just flooded, I remember starting Skoda 120 in winter and listening, as cylinders joined one by one (btw, that car needed depressed clutch, as the oil in transmission became too thick - but it didn't use wide range oil like Felicia)

Have you tried to just disconnect the sensor? Iirc, ECU uses substitute value if the signal is out of range, which is still far from actual temp, but may be closer than whatever is sensor feeding now.

13 hours ago, D.FYLAKTOS said:

When you turn the key to the 1st as i saw twice that you don't wait for the pump to make it's work and you crank immediately, why? This is wrong especially in a cold engine.

FYI, you don't need to wait for pump every time, like with diesel glow plugs. The function is there just to prime the fuel lines and flush gas bubbles that could be there after long standing. Newer cars do that once you open driver's door. Once priming's done, you get full pressure almost immediately and if you want until the pump stops, it's the same as if you didn't wait at all, since the pump doesn't reactivate until you turn the key.

14 minutes ago, Papez said:

It sounds like it's running on two, or even one cylinder. It may be the ignition module, mine was more sensitive to moisture, probably because of cracked insulation.

I agree, although running on one is impossible since it is a wasted spark system. But it did sound like the cylinders were not clearing up, and I thought that this would not happen with a bad ECT except if it is just dumping so much fuel that it cannot ignite.

16 minutes ago, Papez said:

Have you tried to just disconnect the sensor? Iirc, ECU uses substitute value if the signal is out of range, which is still far from actual temp, but may be closer than whatever is sensor feeding now.

From my experience, the dependence of those vehicles in the temp sensor is extreme, i.e. even if its drifiting out of calibratio,n lukewarm starts are impossible. Cold starts usually can be successful with it disconnected but I rarely see below 0C soo, yeah I dont know how it would perform in sub-zero temps

8 minutes ago, Thefeliciahacker said:

Cold starts usually can be successful with it disconnected but I rarely see below 0C soo, yeah I dont know how it would perform in sub-zero temps

True, we are now getting closer to -15, so this solution may not work anymore. Around 0, I'd say it would be still possible, since I assume the substitution value is around 20C (unless the ECU is smart enough to assume the intake temp as the cold temp, which I doubt)

20 minutes ago, Papez said:

FYI, you don't need to wait for pump every time

With Felicia in 1st (cold) start sometimes i forgot it and crank immediately then i always have a ''brough-brough'' rough start, at least 3 times in the past as far as i can remember (2 times was with iridium spark plugs) the car turned-off itself.

I was in a hurry because other cars horning and restart very fast and yes i had the same phenomenon, the third time i raise my hand out of the window and start wave it as i sign ''something is happening" i did a 2 scale process and the car started normally, since then no matter what i turn once wait (even the car is hot) 2 seconds and then crank.

Yes when the car is hot the lines are pressured with gasoline but the bad experience says to act different, maybe it's for my car only.

1 hour ago, D.FYLAKTOS said:

With Felicia in 1st (cold) start sometimes i forgot it and crank immediately then i always have a ''brough-brough'' rough start, at least 3 times in the past as far as i can remember (2 times was with iridium spark plugs) the car turned-off itself.

I was in a hurry because other cars horning and restart very fast and yes i had the same phenomenon, the third time i raise my hand out of the window and start wave it as i sign ''something is happening" i did a 2 scale process and the car started normally, since then no matter what i turn once wait (even the car is hot) 2 seconds and then crank.

Yes when the car is hot the lines are pressured with gasoline but the bad experience says to act different, maybe it's for my car only.

If I don't let it prime it will just crank for longer, but keep in mind my fuel pump is dying

Update - so after a night in the warm garage, we just tried turning it over and it caught first time - still running a bit lumpy, still smelling a faint whiff of fuel, and it needed coaxing to get some revs, but much, much better than yesterday, when it was outside in the cold. My son's mechanic colleague will be coming round with his diagnostic kit later this evening, so we'll see what he finds.

If i remember correct Skoda in the owners manual says that in case that a car turn-off while it's hot and does not start immediately then turn the key to Off then 1st scale, pump the gas pedal few times, let it and then crank.

3 hours ago, D.FYLAKTOS said:

If i remember correct Skoda in the owners manual says that in case that a car turn-off while it's hot and does not start immediately then turn the key to Off then 1st scale, pump the gas pedal few times, let it and then crank.

Close, it actually says for a very hot start to full throttle it right after it catches

If the car has been sitting around for a while and/or is infrequently used over reasonable distance drives then it will have some issues from this alone, cars were designed to be used. If they are to be show cars or very little use and stored away then they need to be in a certain condition before you can do this and during storage, or lack of use, for extended periods then this needs to be done correctly otherwise the lack of use issues will be there on next uses.

3 minutes ago, nta16 said:

for extended periods then this needs to be done correctly otherwise the lack of use issues will be there on next uses.

please quantify extended storage and things to do

Just now, Thefeliciahacker said:

please quantify extended storage and things to do

You already know. Best you put what you do for storage preparation, allowing perhaps for difference in weather conditions, you have current knowledge.

To me two weeks would seem too long not to use a car but I suppose if you're lucky enough to afford or are away for longer then I'd consider someone else driving the car or perhaps doing the storage requirements dependant on how long the car is to sit unused. Cars are to be driven as far as I'm concerned, what anyone else does with them is their business. I've seen enough owners with cars they don't want to drive (or too many to drive) or to drive them as designed when they do actually drive them, or not know how to drive them because they don't drive them enough.

10 minutes ago, nta16 said:

To me two weeks would seem too long not to use a car but I suppose if you're lucky enough to afford or are away for longer then I'd consider someone else driving the car or perhaps doing the storage requirements dependant on how long the car is to sit unused. Cars are to be driven as far as I'm concerned, what anyone else does with them is their business. I've seen enough owners with cars they don't want to drive (or too many to drive) or to drive them as designed when they do actually drive them, or not know how to drive them because they don't drive them enough.

I am pulling my cars off the road for 4 months