Hi,

I have recently fitted a Apexi AVC-R boost controller to my 94 wrx. I raised the boost to 0.95 and all seamed to be ok. I have been using optimax with 1 ml per liter of NF booster. When I ran out off booster I put optimax in on its own and noticed a lot of misfire with WOT between 4000 to 6000 at full boost. But once I used NF again it calmed down but was still there slightly so I decided to change my spark plugs. I used NGK platinum 7's which I have always used. but since the plug change the misfire has come back with a vengeance. I now have huge misfire at full 0.95 boost. The car struggles to accelerate. The interesting thing is, the misfire isn't as bad if I lower the boost to say 0.8 bar.

Could this be the coil packs as my car has done 120,000 miles

any comments!!!

Cheers

Probably coil packs, try your plug gap at 0.6mm, if the misfire clears, it's the coils.

ps I run at 0.6 mm even with uprated coils, so if it works - don't fix it !!

Andy

cheers Andy,

Do you have any idea why it was worse after fitting new plugs?

What differances are there using 0.6mm instead of 0.7mm, what I mean is, is it safe to use 0.6mm

Cheers