Help - A3 1.8 T Sport (150hp) 1998 - Not sparking on 4th cylinder

[betadeltamad]

Have had the car over a year now, done 5000 miles faultless driving until the other day.

Driving back home, it suddenly decided to miss and run on 3 cylinders, it then decided to alternate between 3 and 4 for the rest of the journey and now is only running on 3.

I went obvious and changed the plugs, no difference. Then taking off a coil pack at a time, from left to right, the engine would struggle (as it was only running on 2) until I took the 4th coil pack off and no difference to the lumpy, miss firing engine.

Bought a new coil pack, tried it and still the same :/

Tested the new coil pack with the wiring for 3 and it's fine.

Stumped now, all wiring and connectors look good, why isn't coil pack 4 firing?

Any help would be much appreciated.

 

[<tuffty/>]

Sounds like its the ignition control module... the ICM is attached to the airbox..

<tuffty/>

 

[betadeltamad]

Thanks <tuffty/> much appreciated, my wallets a lot lighter but it's now back on 4 cylinders like it should thanks again!

Quite a common failure then? Looks like the original bosch part that failed, my cars done 130k miles so I suppose cant grumble too much.

 

[makster1978]

intresting,I tried disconnecting both switches on the ignition control module and the car was ready to stall until I quickly re connected,can these just be faulty,i have all the symtoms as above