Papez

Could it be the immobilizer? Diagnostic data line goes through the immo unit, if it's faulty (or removed and deactivated in the ECU), diagnostics won't communicate with the ECU.

Yes, the video covers newer cars with fully electrically driven throttle valve. They use two potentiometers in tandem in both the throttle pedal and valve body to detect fault if one of the potentiometers fail, because stuck throttle valve could be dangerous. These older cars are different, the throttle is moved directly by the pedal and the idle adjustment is basically just adjustable stopper with limited range. This is opened throttle body, where you can see range of the brown part that's controlled by the ECU: Also, forgot to add that there's an idle switch on pin 3 - that lets the ECU know, that driver has let go of the throttle pedal. Unfortunately I still cannot say how do the potentiometers work. I may be wrong about them being independent, but my guess is that the idle sensor only detects movement of the brown part. Btw, you should be able to see some fault codes or weird values in diagnostics, if one of the sensors is bad. Edit: found a video (though it's a 1.3), where you can see the independent movement of the valve and the adjuster. It also shows irregular movement caused by vacuum leak.

It shows the left, but the list below shows PN for the right one under (10). On my car, the bottom trim was one piece, spanning over the entire width. This one seems to be from VanPlus, which didn't have the boot trim, so it's just latch cover.

That's redundant TPS for electronic throttle control. In schematics, it's just marked as TPS-1 and TPS-2, not idle throttle position and throttle position. Felicia uses this weird in-between, where idle position is controlled by the ECU in limited range, but the rest is controlled by cable, independently from the ECU - so it would make sense that position sensors would be independent, too. Also, potentiometers don't fail like this, unless there's a mechanical failure that would keep the wiper stuck in position. They usually fail open or show irregular values over the range. How did you get measurements while powered? Would you be able to get measurements with the engine started?

It looks like you get the pre-facelift frame, those are a bit sturdier, but won't fit facelift tunnel. Facelift frames have weaker tabs which break easily during disassembly. Those have been unobtainable for years.

Can't say, I've never inspected the throttle body, but my guess is that the idle potentiometer is feedback of the actuator, so it doesn't move with the throttle valve, but only when the ECU tries to regulate the idle RPM

Then the only thing I can think of is, that screws in the rear part of the rail aren't seated properly and seat rail stops on them. Or, but I'm not sure if it's correct, I think that rails are moving on bearing balls. Maybe the balls moved around when the seats were out of the car and now they act as a stop.. have you tried to move them back without any weight on them?

According to schematics, pins 1 and 2 are for actuator. Potentiometer pins are 4, 5 and 7 for absolute position and 4, 8 and 7 for idle position (two potentiometers, 7 is common ground, 4 is common voltage input from ECU and 5 and 8 are outputs of each potentiometer). The engine on the photo is EA827. Felicia has an entirely different engine, EA111, which was derived from 0.9-1.3 engines used in Polos.

Does it reach hard stop or just seizes on the way to the back? If the latter, I'd try loosen the bolts a bit, move the seat back and forth and tighten again.

For the next next time, I'll explain how VWs PNs work. First three are model or platform - Felicia is 6U model, so most Felicia-specific parts also start with 6U (the third character is body variant, but in this case, it's the same part for estate and hatchback). It's not a definitive rule, however, Felicia also uses a few 6X* parts (Polo/Lupo platform) or 11* parts (those that carried over from Favorit), plus engine/gearbox parts have their own model numbers. The second three is group - 8** is body Last three is part identifier. Also the last number suggest to which side the part belongs - odd for left, even for right (so parts that have left/right variants only differ on the last character). Additionaly, there's suffix that denotes part variant. It can be 3-character colour code, or 1-2 letter variant - sometimes, it can be nearly identical part that was just replaced during production, different look or function for various equipment trims, or entirely different part that doesn't even fit, because it's meant for different car variant. This is why the Fabia part has almost identical PN. Be careful when looking for parts with PNs, stores often just throw all PNs together under a product and search engines often show wrong part, because there's only one character difference.

W5W is not halogen. A standard Osram W5W has 50lm output, so 10lm/W

2.5W LED is like 15-20W incandescent. You need something below 1W.

6U0885695 H50 (pre-facelift - darker colour) 6U0885695 5SE (facelift) Try searching just the first 9 characters. The last 3 are colour variant.

Don't replace them if you cannot find Gumokov/rubena bushings. They may be still available in some small shops or Skoda parts. Also, Hepu pump I bought some 6 year ago had them, but I don't know about current production. Chinese made mounts are typically very stiff rubber, which won't work well. Anyway, beside the square one, each needs some disassembly and press to change them. The bottom torque mount used to be available as a complete assembly, but that's not the case anymore, sou you'll need a press for that, too. Edit: I'd suggest to change the thread title. It should be descriptive of what's inside the thread.

That's mounting rail for an accessory box that goes under the radio console.

So you didn't get it scanned or tried to start it without sensor?

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)

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. 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.

Simple, I didn't realize the 1.3 had a built-in resistor. 😃 Anyway, looking around, I wasn't able to find any. When I found any listing, it was a mislabeled 2 wire fan for either 1.3 or 1.6 or an unidentified manufacturer.

2-speed FAB for cars without AC is much simpler - here's wiring for 1.9D. The most expensive part is probably the fan resistor. If you get a thermal switch with higher switching point same as the original switch, it will just work the same as original if the resistor fails or if the lower speed doesn't provide enough cooling. Low speed switch would only provide some air movement after the car stops. The resistor limits current to the motor during spin up, which reduces wear.

That's normal behaviour (at least on 1.3, but 1.6 seems to have the temp sensor near the radiator outlet of the thermostat housing -the hottest part of the circuit - as well). The factory fan switch is set to 95+-3deg. It's also placed near the radiator outlet, so it takes some time before hot water gets to the switch, so you can see quite high temp on the dial. More modern cars (even many cars made in the time of Felicia) filter the output from the temp sensor, which is why the needle shows no fluctuations. Felicia feeds direct signal from the sensor to the cluster, so you can observe how the cooling actually works. If you want more stable temps, you need to get fan switch with 5-10deg lower rating. It will result in the fan running more often for shorter periods, which can theoretically lead to more wear of both the fan motor and switch - in practice, I didn't have any issues with this solution.

What do you mean by overheating? Felicia has quite primitive fan switch and thermometer layout, so indicated temperature can raise quite a lot before the fan kicks in. 19 is to the radiator, 20 is return, 6 to the heater, 9 is return. 7 goes to the expansion tank.

Skoda did this decades before VW. 1995 model year started in August 1994. So it should align with UK registration. They did this, because they change tooling during the all-factory summer holiday and to build stock before the calendar year starts.

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. 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.

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. 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. The last sentence applies to this as well. 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. 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.