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DAMN IT! I switched out my battery, now car won't idle

181 Views 5 Replies 6 Participants Last post by  DucaT
Well, my battery went the way of the do-do. So I went out and got a new one. Problem is, now my damn car won't idle. It drives fine, all the power is there, but as soon as I disengage the gear, it falls flat on its face!?!
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Just drive it a little more to give the ECM time to relearn. "All the power" is there because it goes to "open loop" mode under WOT. When in "closed loop" mode at idle (and partial throttle situations), the ECM is still trying to process the "new" info from the sensors.
After learning the hard way.(paid the dealership $100 to clean a supposed dirty throttle body) Start the car, dont touch the gas, and let the car idle for 10 to 15 min. The ECU should have learned enough to keep the engine going.
Also, Check your battery terminal connections.

A loose connection is KILLER on these cars; they want the max amount of contact and electrical flow from the battery they can get.

If there is any loose play or movement at all, the junction will cause resistance, and not provide the proper flow for the engine to idle (that's why the engine can run with any throttle setting besides idle; the alternator is supporting the coils with much more juice)

Just My $.02

funny story:

me and my friend were changing out the battery on my car a few weeks ago. We got the terminal things off and put the new battery in. We couldnt get one of the terminals all the way on so we started tapping it with a screw driver. next thing you know BOOM, i swear it was louder than 10 gun shots. my friend freaked out so bad he fell on the ground and when he woke up he says "i thought my head got blown off"


good times.
Elton isright

Had the same prolem on my car.
The positive battery terminal was loose and corroded. And the "stay put" strap was loose so that the battery was wiggling around.

After I replaced the busted battery clamp and cleaned the battery terminal. Everything was back to normal.

The ECU only needs to "learn" if it has been disconnected for a certain amount of time. The time is in the service manual, but I forget.
Trust me, check the tightness of the bat terminal and make sure the connections are clean.

good luck
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