What can I do about potential engine knock my car runs fine at most times however on every other occurrence at about 3000 - 3500 in 2 nd gear it sort of stutters like a shotgun like for a split second loses power then backfires and off she goes again no problem but it only happens when I floor it in second although I need to drive upto 3000 revs then floor it for it too happen and also I have a simtek ecu and the cel flashes but not when that happens the cel only happens when In 2nd or 3rd when I'm proper giving it some but nothing happens when the cel flashes no power loss backfiring etc the car runs fine any ideas any advice much appreciated

 

doesnt simtek use the cel light for knock warning ?

 

Yes or shift light but wat can I do about it if it is knock

 

Stop giving it so much grief untill you know what's going on or you will end up with a rather large bill.

 

Coil pack..

 

What about the coil pack it looks rather new still

 

I had the same sort of problem when I floored it in 2nd and 3rd and chased it round the engine. I took it to a specialist and found it was the coil pack. They degrade in the inside so it's not visible. I got a 2nd hand one from eBay and now the problem has gone! You can get then from breakers on here for about £25 if its the one that sits on top of the engine.