Skoda Octavia Engine Stalling

[OJazem]

I own Skoda octavia 2001 2.0. since last month, engine keeps stalling:
1) while driving (for 10km or sometimes for 1 - 2 km in distance).
2) or keeping the car idle for 20 - 35 minutes.
and when it stalls, It cranks but does not fireup. unless, waiting for 10 - 15 minutes.

special cases:
1) when I am driving (over 60km in speed), I feel like the engine is holding back and loosing power. As soon as I accelerate, it powers back (or lets say looks like gaining power to run again) and runs smoothly. This happenes, in couple of seconds (like 1 - 2 seconds.). If I don't accelerate, engine goes off.
2) sometime I drive for 4 hours without having this issue (this is rare other than having the engine stalling twice everyday).

 

Things I have done so far:
1) I have changed the battery since it was kinda old.
2) got the car scanned (no issues or fault were found).
3) checked if the car still runs while the battery is unplugged (checking if the problem from the alternator).

This happens since I changed the engine oil ( 20w50 ).

[KenONeill]

@OJazem - Well, you haven't changed the fuel filter, and special case (1) sounds a lot like fuel starvation!

 

Also, 20w50 motor oil is too thick for any Octavia! Change it for a correct VAG 500 specification lubricating oil (probably 15w40 viscosity, but be guided more by petrol or diesel and the specification number).

[OJazem]

@KenONeill - Thank you for your response.

I will make sure to check the fuel filter or get it replaced.
I want to add more info. about the issue:
1) The car stalls only at hot weather (as I noticed), as the past three days were raining and the weather were cool, the car did not stall at all.
2) When the car stalls or about to stall, I hear clicking noise from the relay box under the dash. I checked the relays by just touching and found one of them was too hot compared to the others (which were kida cool).

[OJazem]

As Skoda parts are really hard to find in here, I just got my fuel filter replaced since yesterday. There is difference in acceleration, but the engine still stalls.

 

Any other suggestions?

[KenONeill]

@OJazem - Your 12th July sounds like you may have a bad relay. This will probably throw a fault code, in which case VCDS might tell you which one is faulty (probable codes being things like "Number - Relay name implausible value").

[OJazem]

@KenONeill - well i have two relays that over-heat which are:
1- Relay No - 18 (191-937-503)

2- Relay No - 167 (191 906 383 C)

 

I am not sure if one of these are related to fuel pump as I couldn't find a way to figure out.

 

I am assuming that the fuel pump relay fail, but the only way to start the car without waiting for 5 - 30 minutes after stalling, is to push-start.

Question: would a failed fuel pump relay allow the car to start by push-start?

Note: as I mentioned at the post, the car stalls when I am driving at speed like 40+ km, but I can accelerate to run the engine again. could this happen with a bad relay?

[OJazem]

Edite for the post,

 

Forgot to mention a couple of things:

1. I started to get the immobilise light before the car start stalling, but now I get the light a lot lately (like 85% everytime I want to start the car). So all I have to do is switch off then back on for the light (warning) to disappear and be able to start the car. But I don't get the immobilise light when the car stalls or shut-off.

2. When I force start the car when it's about to stall at low speed or trying to push-start it, I get the oil warning light and the car stalls (this happened to me sometimes).

3. The car looks like to give me more driving time at cold weather. for example: at the morning (weather degree between 17 - 19 C)I can drive for more than 11 km (in distance (depends on weather)) then it stalls, but I can fire the car up after less than 5 minutes. But afternoon(as its hot 25 - 28 C), it drives me less than 9 or 10 km (in distance) and I won't be able to fire it up unless after 10 minutes of wait at-less.

[OJazem]

I have got the car fixed by replacing the crankshaft Sensor. Since then, it's working fine.