wooo1082, Sound like a engine misfire. There are quite a few things that can cause your Mazda to run this way. Bad sensors TPS, MAP, MAF, IAC, O2, failing knock senor, faulty injectors, dirty throttle body, EGR valve, major vacuum leak, failing fuel pump, bad ignition, bad distributor, plugged catalytic converter, transmission fault, etc.etc.. As a first step have the car scanned for trouble codes even if engine light is not on(there still could be a error code) as it may identify the exact problem. Some of the auto parts suppliers offer free code reading like Pepboys, Nappa, Advanced auto parts,etc and some of the guys are very knowledgeable and may have seen the issue often and put you on the right track or see if one of your buddies have one to lend. Some times it does take a better quality scanner that can read live data, such as fuel trim/sensor operation/etc. and for this you may have to go to a good local auto repair shop. Good luck. I hope this helped you out, if so let me know by pressing the helpful button.