Black sparkplug/knocking...long

[bobtodd]

I just put in 30lb injectors with a Pro-M 75mm. Well, I took it for a test drive and it seemed to run alright. There was a bit of a hesitation when starting out in first and it felt like it would miss until it got into the higher rpms and then smooth out. At WOT the car ran pretty good. Then after awhile of driving the car I noticed it would chug when taking off in first gear...like a plug wire was off. Well, all plug wires were on and everything looked in place.
The next morning after having installed the new injectors I took the car out. I hammered on it and it went pretty good...still chugging when starting out in first. Got to the end of the road, turned around and hammered on it again....into second I hear a knocking. I let off the accelerator immediately. My oil pressure was normal. I drove it home and nothing sounded out of the ordinary...oil pressure and other gauges all stayed normal....and I do get a nice high oil pressure reading. I decided to slowly get on it again. I could slowly accelerate and hear no knocking. Attempt to give it WOT and thats when the knocking will occur. I pulled the spark plugs and they were all brown except for the number seven...it was a sooty black. My main question out of this is.....will a cylinder that isnt firing cause an engine to knock? I've got a few things to look at. I will try switching injectors around to see if it is a faulty injector(stuck open) causing that plug to go black. Check to see if pllug wires hooked up and not crossing each other. Any other ideas? I will check to see if I have a bent push rod too. I didnt have much daylight tonight, but I cranked the engine over with the valve covers off(and coil unplugged) and all the rockers would go up and down...could this rule out lifter problems? I did have a ticking sound but figured it was my rocker arms...I've got 1.6 roller tip rockers. Any ideas would be great. Thanks!

[bigblockcoupe]

sounds like spark knock or detonation would be another term for it. how much timing are you running and what kind of gas? if you have good gas(not 87 octane) in it then i would try retarding the timing a couple of degrees to see if it goes away.

[bobtodd]

I guess I should describe it more as a tapping. What causes a plug to go black?.....and only one plug. I checked the pushrods and they look fine. I cranked the motor over with the valve covers off and all the rockers went up and down.
I had 92 octane with 104 octane boost with timing at 16*
I put new plugs in and am waiting for the delivery man to bring my intake gasket...he should be here today. When I took off my upper intake the gasket was in two pieces.
Anyhow, if anyone has some info...