Low Idle After New Battery

[functionFiRst]

Hey everyone, I just replaced my battery because my light went on, and now My car idles at 500 RPMS.

I just changed my alternator and everything works, even better because of the new battery. I'm just wondering why it Idles low now.

If anyone could help it would greatly be appreciated! Thanks in advance!

-Mike

ae86/jzz30

[SKperformance]

Does it cut out or idle rough?

[AWJ]

If it idles without any problem, it is idleing lower because the new battery has reduced the load on the alternator. Sounds like your alternator was working double time to charge your battery.

[Lextreme]

Since you replaced the battery. You have reset the ECU and the ECU is trying to re-learn the new setting. Takes a while before it runs properly.

[functionFiRst]

It doesn't cut out right after, just idles rough. I was just wondering if there was a way to adjust the idle, or should I just give it a couple days, so the ECU get's used to things? thanks for the help by the way fellas!

-Mike

[AWJ]

Mike,

When was your last tune up? How many miles are on the car. It could be several things. Try our search feature. We've gone through this trouble shooting issue before. Anything from a dirty air filter, to a bad plug, to a loose vacuum line. You will need to make sure all systems are operating correctly first. Do this before you go adjusting things. I would recommend running a mil check or fault code. PM me if you do not have the procedure. If your pm does not work, post your email if you feel comfortable with that and I'll send you the procedure. There is also a site through alldata - what little bit is free, that give the procedure. I linked to it in the past.

Best of luck.

[SPORTcoupe300]

Hey Mike,

The ECU will re-learn within the next few days and you'll be back to normal.

[functionFiRst]

Thanks AWJ and Sportcoupe300! Yeah I'm in Dire need of a tune up which I'll take care of next week, as soon as my tests are all done. I'll definitely take advantage of the SEARCH function next time.

I've been a little busy, I just sold my ae86, so I haven't had time for the tune up. But project SOARER is back in business.

Thanks again guys!

-Mike