My idle has been rough since I got my car a couple months back ('91 N/A in case ur wondering). I just assumed it was a vacuum leak and had planned on getting it fixed whenever i had the time. Just last night though I noticed that my idle changes in response to me doing anything in my car that takes power from the battery. Like, if I move the power window switch my idle will move around or if I turn my head lights on/off it will jump around for a sec. Every time I start my car up it will jump around for a few seconds then rest finally at 750 or sometimes just die all together. Sometimes it gets better after i drive for a few and others not, other times it will just get worse and wanna die every time I stop. Could this be caused by my battery somehow? I know there are a thousand threads out there about rough idle and trust me, I've probably read the majority of them but I never saw anything like what mines doing with the electrical and what not. Any help ya'll can offer up is, as always, greatly appreciated

 

thats because you putting a load on your alt. and therefor putting a drag on the engine inturn changing the rpms

 

well i understand that, i just didnt really understand how it could make that much difference and didnt think it was normal. wouldnt u think if my alternator was working like it should it would have more than enough power to handle the draw from the windows etc. without causing my idle to change or am i wrong? i havent had my rx for that long so im still kinda new to the rotary world and just thought this was strange cause it was never like that with my 240 or any other cars ive driven

 

My car does that to. If I switch to an FD alt. do you think my idle will still move around when I use my power windows, turn on/off my lights, or step on the brake at idle?

 

Could be a bad ground.

 

weak altinator. . the battery should have no effects on how the car runs. You can disconect your battery while the car is running. .