i have a 86 gxl rx-7 and i was wondering if you guys can help me figure it out myself so i wont have to take it to a mechanic first thing is that my car will not pick up higher than 70 mph and when the rpms reach 4500 it starts jolting nasty and id be flooring it and and my lights from the tach dont light up do you guys think it electrical or engine please let me know thanks

 

it sounds like an electrical problem to me. will the lights on the other gauges come on?

 

just read somthing kinda liek this its in the pinned techs, check grounds.