Redtop sr20det , overfueling on back cylinder

I'll try to give a shortened version here - basically I have a redtop sr20det rebuild with a omex 500 ecu wasted spark ignition and 560 topfeed injectors, along with a Greddy copy inlet. I've just replaced the coil pack and leads for new ones,

I took the car out for a short drive, warmed it up, drove it up with positive boost through the gears. When I pulled the plugs, the rear cylinder was pretty black and when I shone a torch down the plug hole it looked damp on top of the piston, the rest looked dry.

Two things I was thinking; my fuel rail supply in was going into the centre of the fuel rail rather than at the end, the other was the Greddy copy inlet.

Could this cause the back cylinder not to get enough air? any thoughts ? :sxoc:

Your plugs won't tell you anything if you have let it idle or have coasted down. All it says is that the engine was possibly richer/different burn on that cylinder at the moment you switch it off.

The only way to tell what it's like on boost is to nail it through the revs and turn the engine off so that the plugs retain the colour of the burn at that specific point.

Also what's made you check? Has it given you any symptoms that made you feel it needed looked at or was it just that you noticed in a plug change?

Is the injector leaking slightly as was said above to check plugs you need to kill the engine at the point you wanna check

It was once I put the engine back together with new head gasket & Tomei Poncams cams , it was on the hub dyno when running the cams in , when cams were run in the plugs were removed to do compression and leak down test , noticed the plugs were like this . I got the spark checked at the plugs , which wasn't good , the leads were checked for resistance , so fitted new leads and got new type of coilpack. I will check injector thanks .