Hi everyone

 

I have a imported 1998 Version 4 imported STI 4door, i have developed a misfire between 2-4k rmp on full throttle, seems to occur on full boost and clears once above the effected rev range. once above 4k it pulls like a train but it seems to drop into a misfire whilst building boost. Ive cleaned the MAF/checked all silicone joiners, it has got iridium plugs/standard intercooler/standard recirc BOV and Ive cleaned all of the visible electrical connections. Any suggestions/common failures?? it has covered 160,000 miles with replacement head gaskets/skim heads 4,000 miles ago. never had any running issues before and  i am  scratching my head as to why its happening now!

 

Cheers

 

Yoss

checked the spark plugs? also could be a lead/coil pack issue

Yeah I will change the  plugs, its got Iridium  ones in at the moment.   (not a great fan of those) but shall fit normal NGKs and see how it goes.

  Thanks Yoss

NGK pfR6 for normal, pfr7 for tuned are the norm

Cheers will pick some up tomoz..

Well I bought a set of plugs, and some injector cleaner. Decided to use the cleaner first to see if it made any difference and after adding it to  a couple tankfuls  the problem has gone!!  Will fit the plugs at a later date. So all good..

     Cheers Yoss.