Rough Idle after dead battery. - Toyota Tundra Forums : Tundra Solutions Forum

shelby427uk · #1 (**permalink**) 09-10-2007, 07:21 PM

My wife went to start her 2005 corolla S this morning to be greeted with a completely flat battery out of nowhere, it was fine last night and it's a daily driver with almost 100k miles. I came home from work to see what the problem was, and after a jump start, the alternator was charging just fine so the battery was the problem. I replaced the battery and now the car idles verry low, like around 350 - 400 rpm. I noticed everything on these things these days is computer controlled. There was no check engine light either. Always properly maintained. The low idle lasted 30 mins while driving over town and then now idles fine, but under hard acceleration it feels like it's not fueling properly, spluttering like it was a rich mixture or something? Anyone have corolla troubleshooting experience seen this before or have any ideas what it could be???

glow-plug · #2 (**permalink**) 09-10-2007, 09:06 PM

No idea.
Got a multi-meter?

Check the battery voltage not running and running, compare the running voltage to a reading right off the back of the alternator.

Were the battery posts and cables cleaned when the new battery went in?

shelby427uk · #3 (**permalink**) 09-12-2007, 07:37 PM

I checked everything out. I'm a qualified mechanic, but back in the days of carbs, pionts, lift pumps and cables!! long gone now i know. Alternator charged good and the battery posts were nice and clean. It has not done it again though. I'm wondering if the computer needed a few minuites to re-set after having no power. It does not seem likely, otherwise it would be a known problem for anyone that has ever changed a battery. I'll just see how it goes. Any more trouble and it's going straight to the dealer to be traded!!...this is not what comes from buying a Toyota

glow-plug · #4 (**permalink**) 09-12-2007, 08:53 PM

Not sure if Toyota's CPU's do learn after loosing power, but it's possible, some GM's do that.

9phil9 · #5 (**permalink**) 09-17-2007, 11:45 PM

Once you disconnect the battery, the ECU will have to go through a complete learning cycle that will last approx. 200-300 miles.
During that time, it will "learn" how much fuel to feed your engine, under a variety of temperatures, and load conditions.

I'm pretty sure this is covered in the owners manual, but if not, the dealer will be happy to explain the proper procedure for changing out a dead battery.