Misfiring help
I need help. I have a 1991 Nissan Skyline R32 GTR, I recently had it in the shop getting intercooler piping, new ECU HKS Fcon V pro and a tune. Got 579 to the wheels and was running great for about a week. Then one morning woke up and it sounded like a Subaru and it blows smoke out the exhaust. Did some trouble shooting and found that when I unplugged number 2 and 4 coil pack the engine idle didn't change. red out the coil packs and checked the plugs, all good. even swapped coils around with no change. The plugs are wet with gas so I did a old school spark test in the block and getting spark. ordered new coil pack wire harness and still no change. swapped out the PTU(coil ignitor unit) with a known good one and still no change. Did the self diagnosis and got code 21, Could it be the tune is causing this, I mean it just started one morning when I started the car and it ran fine the night before. Thanks.
Mods on the car
1.2mm aluminum head gasket
tomei pons cams
tomei m8270 turbos
HKS intercooler piping
HKS boost controller
HKS Fcon pro v(no MAF's)
nismo 600cc injectors
walbro fuel pump
full 3in exhaust w/cat delete