I have a 1985 mazda rx7 GSL and it starts and runs but it will not hold an idle. If I start it and give it gas while in neutral it is fine it gets a little rough when driving but will not idle at all. I just replaced the distributor cap and rotor. I also adusted the idle and I still dont know what is going on any suggestions??

 

You might have a clogged idle circuit .

 

Start by checking for vacuum leaks. A leak can cause an engine not to idle. Next, check the carb's idle speed adjustment and mixture. Adjusting these per the FSM can really improve the engine's running condition. I would start there.