I have a 57 Plate 1.2 HTP Fabia (BBM Engine) - milage is high 147000 - but has a full service history and has been well maintained all of it's life.

It has a misfire on cylinder 2 - the misfire seems to be intermittent - and it will happily rev at 3 to 4 thousand without any knocking or strange noises

However the ECU flashes an error (16686 - misfire in cylinder 2) and from that point the car will not get above about 1800 revs it shudders badly and cylinder 2 seems to have been shut off (removing the connector from the coil pack does not change the way the engine behaves)

If I delete the error and restart the engine it will go back to 3 to 4 thousand revs until the engine light starts flashing again.

I have tried changing the coil packs round and have fitted new plugs.

Can the ECU switch off a cylinder either by cutting power to the coil pack or to the injector?

Sorry if these seem silly questions but I am new to this - the last time I worked on an engine it had a carb and distributor and no ECU!

I have asked garages locally to look at the car - but they just say (without ever looking at the car) it would be an engine rebuild  - cost is more than the car is worth - we don't do major jobs like that- just scrap it - . But it is in lovely condition apart from this problem.

Any advice would be greatly appreciated

21 minutes ago, graphite58 said:

Can the ECU switch off a cylinder either by cutting power to the coil pack or to the injector?

Yep, if misfires exceed a threshold number in a given time, I think fuelling to that cylinder is stopped. Cycle the ignition and the misfire counter is zeroed.

 

Compression test is your next logical move.

Edited 10 August, 20187 yr by Wino

Similar to an old thread on here or mk 1 that turned out to be a faulty fuel injector.