My rebuilt d16z6 with y8 head bogs/hesitates/backfires when I give it gas.?

Its fine on light throttle, but trying to get into traffic with maybe 1/2-3/4 throttle it hesitates and backfires. I have the mechanical and ign. timing almost dead on. Also the timing belt is slapping the timing belt cover. And my speedo and temp gauge jump up and down, even just cruizing they jump, but they are reading. I have oil pressure, water temp, and a tach wired to the battery and their own switch, and they are also jumping. I have a chipped p28 ecu which blew the acg(s) fuse when it was hesitating on WOT and now when I swap between the stock p05 and chipped p28, so im currently on the stock p05. The ecu, plug wires, fuel pump and filter were all fine before I did the swap. Do I have a short some where? What should I check? I have a dmm, but dont really know how to use it. My thermo stat housing ground and tranny ground are tight and clean, but only had .6-.7 continuity. Sorry for long question, just trying to cover the basics.