If you have a power logger ,scanmaster and a wideband. what are they doing ? Don't keep going wot if its lean you will hurt something.J&E pistons will melt trust me. Performance will not change intermittently with broken valve springs. When they are broke it will run like crap all the time.weak springs can cause problems but not the problems your having Did you check volume of fuel? It sounds like its running out of fuel. Is the wideband pegged lean when wot? scanmaster showing lean? Data logger info.Im not trying to be an ass but do you know how to read the datalogger and the scanmaster? there is a wealth of info right in front of you.If your lean you will see it on all three. I don't see any info about what fuel pump your using and don't say its stock.Do you have a hotwire kit? You are moving a good amount of air. I would have a double pumper with your mods just to be safe. I would limit on driving it or at least getting into any serious boost until you get it figured out. Start posting scanmaster info and datalogger files because if you need help reading them there is plenty of people on here that had the same problem your having and can probably help you figure this out just by looking at the info you post. Throwing parts at it might fix it but you can go broke in the process. Again not trying to be a jerk just trying to help. Like stated above check ground. run a jumper cable from battery negative to engine and run one from the body to engine and drive it like that