I have B16A engine. My modifications so far are: intake, header, exhaust, MSD SCI ignition, crane cams PS91 coil, Spoon sport sparkplug cable, fuel pressure set at 4.2 kg/cm2. I used denso iridium IK20, the gap I set it at .043 (factory setting). My question is after just around 15 miles I used the car and I checked at the sparkplug and the sparkplug become black on the sparkplug ring. Is it normal or I running rich. I did reset the ECU but it doesn’t solve the problem. Any suggestion? Thanks.

 

this is normal carbon build up....depending on the octane you burn.....try to get 94 synoco it burns cleaner longer and hotter but as far as that its normal......do you have any other symptoms of running rich? lack of power hard starts massive backfire black smoke etc,...?

 

No, everything is normal. Just wondering if this is normal. Thanks. Is it by lowering my fuel pressure or change one step hotter sparkplug, my car will burn cleaner?

 

what octane are you using....i wouldn't even worry about the carbon on the plugs its totally normal

 

Okay,thanks. I use 95 octane,but I don't live in the US.