Battery troubles.

[vijen6]

Hey guys,

My battery died yesterday and left me stranded. I paid for a jump ($55 from AAA) and got the car back home (45 minute drive). This morning it didn't start again, so I walked to Kragen and got a new battery. Its an Autolite 48-84.

I thought 48 was our battery size, but this one was physically a bit smaller than the OEM battery. They didn't have one exactly the same sized as ours, but the guy looked it up though, and said this should work for the car.

Now its installed and cranks, but at idle, the car is not staying at the same RPM. Before, it usually stays at 800rpm flat, with no movement on the needle, but now its fluctuating down to about 600 and then revs back up to about 900 automatically and then drop back down to 600. This would happen constantly.

Car ran strong yesterday after I got the jump start, but haven't been driven since I installed the new battery. The fluctuation rpm worried me and I turned it off after the car idled for about 3 minutes and didn't get better.

Did I buy a bad battery or the wrong battery size ? Or could it be something else ? Should I take it to a shop ?

Thanks.

[Loren]

Size 48 is correct.

After the battery has been removed the engine computer needs to "re-learn" its adaption to air density, temp and your driving style.

Drive it for a couple of days and if it doesn't get better let us know.

[vijen6]

I just took it for a 5 mile drive, and it got a bit better. Not much, its fluctuating still but less. Maybe +- 150rpm instead of +-200 from 800. Hopefully it will be better within a day or two of driving.

Thanks.

[vijen6]

Good news guys. Problem is gone. Car is running strong and idling smooth. It relearned the map within 20 miles. LOL though because it remembered my seat settings, but forgot the engine settings.

Weird though because when the old battery died, I was still able to have stereo and lights and gadgets, so it wasn't completely dead, just not able to crank over.

It didn't give any warning though. I started it and drove it just fine 30 minutes before and when I got there, it just wont start again and just died. Oh wells.

Thanks guys.

[jmatta]

Your car after 20 miles is just beginning to relearn everything. If you had access to test equipment, you'd see that most stages of the DME are "not ready". After a disconnected battery, it can take a week to get the complete system back to a "ready" status. We know, because my friend's battery died this spring after winter storage (with a tender) and the car would not pass emissions until everything was "ready".