(Sorry for mistakes (english isn't my mother language) ) So, I have this problem - my Fabia 1.4 MPI 50kw starts pretty hard, engine cranks but it won't start (and it doesn't sound like it would like to) after few seconds of cranking it starts, but usually I have to put my foot on gas pedal. However this happends only if the car is cold or if it's first start in a while (if I start it and then turn it off and start it agin In few minutes it starts right off). When car is running there are no problems with idling or fuel consumption, but power is slightly lower than it should be (I think). Car returned from service few weeks ago and timing chain, middle and back exhaust part and all filters (inc. fuel filter)  were changed. Next week thermostat should be replaced because it takes too long to warm the engine (even after 6 miles engine isn't 90°C). Does anybody know what it could be ?   

Replace the ECT sensor as well as the the thermostat.

ok, but would solve problem just with warming up engine, am I right ?

No, a faulty ECT sensor will affect the car starting when cold too. 

 

The part number for the full thermostat housing complete with thermostat and sensor is 047121111S

 

Edited 23 November, 20187 yr by TMB

Because it is sending info to ECU to set air/fuel ratio that's right, but it doesn't explain that "second start" (if I would just restart the engine right after start) because temp. sensour woid read same (however wrong) temperature, so ECU would set the same lean/rich mixture as before 

 

Edited 23 November, 20187 yr by storext

Replace with part number 047121111S and then see if the problem goes away. If not you can look further but the ECT sensors do tend to fail.

As I said, through next week thermostat will be changed, but if nor thermostat or ECT sensor replacement would help next thing is probaly fuel pump right ? 
Now I was checking prices of thermostat (whole) in my country original part (mede in Czech republic) costs 26.55 euros (so 24.5 pounds) and that isn't so bad

Edited 23 November, 20187 yr by storext

I don't know. Have you had it scanned for fault codes?

Edited 23 November, 20187 yr by TMB

Yes, twice - once with E4T diagnostic tool (originaly for Skoda - made by one company owned by Skoda / VW goroup) no codes. Then with (I don't really know what kind of diagnostic toll it was) - my friend used it when car didin't want to start at all (it was just blown fuse  ) and it also showed no codes 

Edited 23 November, 20187 yr by storext

OK. I reckon it will be OK after the new housing is fitted.

Ok thank you for your replies I will write her results as soon as I get them  

OK 

On 23/11/2018 at 22:37, storext said:

(Sorry for mistakes (english isn't my mother language) ) So, I have this problem - my Fabia 1.4 MPI 50kw starts pretty hard, engine cranks but it won't start (and it doesn't sound like it would like to) after few seconds of cranking it starts, but usually I have to put my foot on gas pedal. However this happends only if the car is cold or if it's first start in a while (if I start it and then turn it off and start it agin In few minutes it starts right off). When car is running there are no problems with idling or fuel consumption, but power is slightly lower than it should be (I think). Car returned from service few weeks ago and timing chain, middle and back exhaust part and all filters (inc. fuel filter)  were changed. Next week thermostat should be replaced because it takes too long to warm the engine (even after 6 miles engine isn't 90°C). Does anybody know what it could be ?   

 

 

hello did u fix the problem ? i ask that because i have the same problem with my car 

i have the same problem and a mechanic told me that the problem might be the camshaft sensor 

No, I haven't tried yet (because mechanic just before few days ordered the part so I am waiting for replacement) but today I was thinking about disconnecting sensor and trying starting engine like that (but I don't want to drive like that because mixture may be too rich and I could damage catalytic converter (or both of them because in my AQW engine I have two )) I'll tell you how it went

So, I tried disconnecting temp sensor and it did not help - car started even harder. But it will be replaced  anyway (because thermostat isn't working and I want whole thermostat body to be changed). So next thing on "list" is fuel pump because if fuel pressure isn't high enough it could cause these problems. Or some pressure leak - some check valve or something like that, fuel pressure regulator is OK because it forms one component with fuel filter which has been changed last month or so. But if it is fuel pump it's ... pretty bad 

 

Edited 8 December, 20187 yr by storext

7 hours ago, storext said:

No, I haven't tried yet (because mechanic just before few days ordered the part so I am waiting for replacement) but today I was thinking about disconnecting sensor and trying starting engine like that (but I don't want to drive like that because mixture may be too rich and I could damage catalytic converter (or both of them because in my AQW engine I have two )) I'll tell you how it went

 

There is only one catalytic converter but two lambda sensors.

 

 

 

Edited 8 December, 20187 yr by TMB

Ok my bad. One lambda probe have been changed (1,2 years ago I don't really remeber) however the other one not. Could it be it ? But probably not because lambda probe starts it function when the engine is (at least a bit) warm and not right at the start. Am I right ? In Monday car is being sent to service - thermostat finally came so it is going to be replaced (whole thermostat body) so I will tell you how it went, 

Edited 11 December, 20187 yr by storext