Afternoon,

Car's just picked up a misfire (picture below). Presumably this is typically coilpack? The plugs are 1500 miles old and gapped correctly and engine is freshly built.

2009 STi hatch

Cheers

 

Try moving the coil pack and see if the fault move . . .

 

Could also be air leak..my recently purchased hatch sti part blew the intercooler hose off under the intercooler.
caused a number of issues and one was a misfire.
Hose reseated and clamped and car back to normal.

 

Thanks for the replies chaps. So I just changed cylinder 1 coil with 3 and went for a drive and now bizarrely the misfire has totally gone.

Presumably of the coilpack is faulty it's an intermittent thing OR presumably the coil pack just wasn't sat right on the spark plug..

I'll update in a couple of days if it returns.

Mega props though to Alan at AS Performance. Spoke to him this morning for price and availability of a new coil. He didn't have one on the shelf so whilst he sourced one, sent me out a used one FOC to help in my diagnostics. Should see that tomorrow but you don't get better service than that

 

Sorted: was the electrical connection to cylinder 1 injector wasn't quite clicked in.