My mk1 Octavia (AGR engine, 110k miles, full service history) has developed a problem. When slowing down to almost a stop, pressing the clutch and braking, the engine revs drop to about 500 - 600, and it runs rough, it sounds like its only firing on 3 cylinders. A quick 'blip' of the accelerator puts it back to normal idle speed of about 850. If i'm stuck in traffic and only moving a cars length at a time, sometimes it does it again, sometimes it stays at normal idle. Once the accelerator has been 'blipped' it will sit quite happily at normal idle e.g. sitting at traffic lights. It happens when the car is hot or cold. I've tried knocking it out of gear and using the hand brake to slow to a stop to see if its brake related, but that seems to make no difference. My reason for trying this was to see if there was a servo air leak. It starts and runs fine otherwise. Anyone had anything similar happen?

need to have fault codes read as it could be few things

fuel filter

blocked injector

maf

air filter

throttle sensor

egr butterfly sticking

In the summer with the AC on I get the same simptom on my 1.8T....hate it!

Cleaned and changed everything,TB,connectors,vacuum pipes,filters....nothing ....the engine is allmost dying when the car allmost stops in neutral

In the summer with the AC on I get the same simptom on my 1.8T....hate it!

Cleaned and changed everything,TB,connectors,vacuum pipes,filters....nothing ....the engine is allmost dying when the car allmost stops in neutral

From memory, there is a wire that runs from the fan controller to the ECU. If this wire is broken you will get those sysmptoms.

<p>

My mk1 Octavia (AGR engine, 110k miles, full service history) has developed a problem. When slowing down to almost a stop, pressing the clutch and braking, the engine revs drop to about 500 - 600, and it runs rough, it sounds like its only firing on 3 cylinders. A quick 'blip' of the accelerator puts it back to normal idle speed of about 850. If i'm stuck in traffic and only moving a cars length at a time, sometimes it does it again, sometimes it stays at normal idle. Once the accelerator has been 'blipped' it will sit quite happily at normal idle e.g. sitting at traffic lights. It happens when the car is hot or cold. I've tried knocking it out of gear and using the hand brake to slow to a stop to see if its brake related, but that seems to make no difference. My reason for trying this was to see if there was a servo air leak. It starts and runs fine otherwise. Anyone had anything similar happen?

Sounds like a sticking EGR valve or a break in the pipe between the exhaust and the EGR. Blipping the throttle at idle sets the EGR to minimum duty cycle.

Best to get the car scanned for faults.

where is it? a picture please?worth checking

I don't think is fan related,when the AC is off the rpm still drops but alot less.

But that happens only summer when is hot!

where is it? a picture please?worth checking

I don't think is fan related,when the AC is off the rpm still drops but alot less.

But that happens only summer when is hot!

I'll get the details for you and post back tomorrow. The fan controller (under the battery tray) controls the fans and the a/c. The wire signals the ECU that the a/c is on, so it can open the throttle a bit to account for the load.

yes,you are right...I feel like the TB isn't ready for an extra load (AC)

Ok then,I'm waiting your post to clarify me thanks!

yes,you are right...I feel like the TB isn't ready for an extra load (AC)

Ok then,I'm waiting your post to clarify me thanks!

The wire passes through pin-8 of the orange 10-pin connector in the plenum chamber connection box (under the wiper motor).

It is a blue/red wire and is the signal that the a/c is switched on. Sometimes it comes from the fan controller (pin-8 of 14-pin controllers), sometimes it comes from the pressure switch and sometimes from the a/c switch/climatronic.

If you give me a year/engine code and if you have climatronic, I can narrow it down for you.

Is a 2001 1.8T AGU engine 110 KW, climatronic

thanks!

Is a 2001 1.8T AGU engine 110 KW, climatronic

thanks!

Climatronic, 12-pin connector, pin-3 --> Loom, 17-pin connector, pin-3

Loom, 17-pin connector, pin-3 --> Plenum connection box, Orange 10-pin connector, pin-8

Plenum connection box, Orange 10-pin connector, pin-8 --> ECU, 52-pin connector, pin-10

Wire colour is blue/red throughout.

thanks again,I'll check them!

I have the exact same problem with my 2.0i 85KW AQY Y2000 petrol engine.

Can someone help me solve this issue since I've run out of options?

There is no codes, everything seems to be in order.

It drives me nuts since the engine stalls (for a second) from idle to acceleration because of this.