qtrmile66

appreciate any and all help on this guys. i have researched the problem a bunch and found there to be people with the same issue but no one has talked about a soultion if they found one. quick rundown, 94 z28, m6, 93k, bought recently. when i got the car it was bone stock with all original papers etc. had a skip. found a failed #7 plug wire and fouled #7 plug. fixed that and car ran great. did not drive the car much before installing bolt ons. car now has k&n cai, magnaflow exh, hypertech 160, new gm plugs, taylor t-volt wires, t-body airfoil, bypassed t-body coolant hoses, water pump, optispark, msd streetfire coil, (spaced away from the head) trick flow elbow. when first got car back together it started and ran unreal, like a new car. it now will occasionally kick back when cranking the engine hot or cold. if you stab the gas from a neutral idle it stumbles and picks up revs poorly. if you stab the gas from a partially open throttle it revs much better. when cruising in upper gears 2500 rpm or lower and try to floor it slowly or quickly it will fall on its face and sputter, sometimes detonating. changing the coil improved this slightly but still there in 4th and 5th always. i consider myself a good wrench and have double checked all my work but would appreciate others input.