No engine power after battery disconnect

[kfbrlinton]

Three times I have had the battery disconnected during maintenance on my daughters 2000 4 Runner: MAF; spark plugs; etc. Each time after reconnecting the battery and starting the car it had no power. You could step on the gas and it would not take it like a engine without spark advance. However after driving it around the block it got better like the computer had to relearn how to control the engine. Any idea what causes this???

[Scuba]

Three times I have had the battery disconnected during maintenance on my daughters 2000 4 Runner: MAF; spark plugs; etc. Each time after reconnecting the battery and starting the car it had no power. You could step on the gas and it would not take it like a engine without spark advance. However after driving it around the block it got better like the computer had to relearn how to control the engine. Any idea what causes this???


When you pull the power from the ECU it does in fact "forget" all things timing, induction, and fuel related and it normally takes a few driving cycles to get back to normal.
Though, it shouldn't be as drastic of a power loss/ spark advance symptom like you are experiencing.

FWIW, replacing spark plugs and a MAF does not necessitate disconnecting the battery.

[YotaFun]

Clean the throttle body, when it relearns it thinks that the throttle body is clean of debris and carbon build up.

We do this on a regular in the shop when we have to replace a battery in a customers car, especially the corollas.

Cleaning the Throttle body makes it sit at the clean position so to speak and to computer can compensate for its position