I have a tbi 350, Recently i could run up to 20* base timing in it, the engine loved it! had great throttle response, ran quick! broke the sun shell on the tranny lol. But now, after rebuilding the 700r4, giving it roller rockers, an ignition box and a 670 tbi, I can't run timing in it like i use to, lots of knocks now. I looked at the timing with a light, and i was getting a knock or 2 at only 6* base timing. When i hold the throttle at 1500 or so, it will jump up to that, then drop to about 1000 with the same throttle. I got a code 42 not too long ago, I don't get it anymore, but i looked at it again with the light, and with the spout sensor disconnected, the timing would retard as you bring the rpms up. So i shut it off to think about what could cause this. When i started it again, spout sensor disconnected, The timing was fine. Stayed where it should be even with rpm increase. Then all of a sudden it idles up, and i can't even see the timing mark on the wheel anymore Not sure if its wayyy advanced of retarded, but its not supposed to do that. When i shut it off, restart it, its fine again. Just today, i did it again with the spout sensor connected this time, and i brought the rpms up to 1600, and the timing would advance like it should, then in one blink of the light, its back to the idle timing. rpms seem to stay the same, i let off, bring them back up, does the same thing. I've replaced the knock module, I think it could be a wiring problem or bad connection. But i still don't know why i got a code 42. and i haven't replaced the ignition module...I'm stumped, any ideas?