Hi, I'm new to this site but found it cos I need help with my Mk1 Octavia Vrs. The car has run sweetly for 6 years but has started miss firing on long journeys. Fault normally occurs after about 100 miles when engine starts missing on one, two or three cylinders. If the engine is shut down for say half an hour fault still persists but if it is shut down for some hours the fault disapears. If I put my foot down when fault is in progress it makes things worse but if I apply a very slow increase in acceleration the fault level appears to reduce ( ie. it feels like its firing on three rather than two ) Can anybody suggest whats causing this? ( injectors, coil pack, EMS???? )

Edited 25 February, 201115 yr by rdsskoda

Welcome to Briskoda, not sure on your query but sure someone will be able to help.

Welcome from me too. I have moved your thread to the Octavia I forum where it is more likely to be answered.

coil packs would be the first thing I'd check. Have you done a scan on the car for fault codes?

coil packs would be the first thing I'd check. Have you done a scan on the car for fault codes?

Hi Mike, thanks for that - garage have done scan but all they say it's telling them is car is missfiring - well I already know that!

Hi Mike, thanks for that - garage have done scan but all they say it's telling them is car is missfiring - well I already know that!

What a helpful garage....not. If they plugged the car in to a diagnostic then there should be a fault code that would indicate the area of problem. i.e which cylinder is missfiring

you could try unplugging a coil pack at a time and checking if there is any difference to the running of car. When there is no difference then that would indicate the duf coil pack. Obviously if you have a intermitent missfire then this is no help to you.

Agreed, you need to see if the fault 'moves' between cylinders with the moving of packs. An ebay VAG COM cable and free software will help with this (£8-9 for the lead)

get someone with VAG comm to run a log, you can log the number of misfires which should indicate which cylinder its misfiring on. Any descent VAG specialist should be able to sort it easily. Also check the coil pack wiring as this is prone ro cracking due to heat from the turbo.

Coilpacks just replace the lot and make sure you get the ones that bolt down there less likely to misfire by about 90%

If the coilpacks are fine / replaced with no effect, it'll be the 5-wire Lambda sensor (pre-cat) on its way out / failing.

I'll bet £5 on it.