Vauxhall Astra cylinder 4 misfiring

hi it soundslike your coil pack very common quick test for your injector just remove the electrical connector if the engine starts to run roughly its more than likley your coil pack

Have you had a look at this similar problem: cylinder 4 misfiring

This message was auto-generated based on a user suggestion.

hi thanks for your reply will pass the info on....the problem is intermittent seems to work fine then judders loud noise like a motorbike engine management light comes on flashing then solid then it stays on and then the car can seem absolutely fine!...could this problem be linked to me having a new fuel tank replaced (it was a modified fuel tank) someone else said my injectors needed cleaning do you think maybe injector fluid is worth trying before changing coil pack...i previously had code saying something about fuel too rich which doesnt seem to come up anymore could this have caused a this problem...my car is currently being fixed via insurance although my own mechanic doin the work but he is going to charge me for coil pack as he said its nothing to do with wat he has done...please help my car has been playing up for 6 weeks now many thanks in advance

the pipe left off if its a breather should be connected to a carbon canistor.The fuel system should be sealed and vapours pumped back into inlet manifold.I would get this checked out first and rectified before doing anything else.