Just put new battery in 01 4Runner. Engine turns but won't fire. Engine ran fine before replacing battery

when a battery is completely drained, it shortens the life or could kill it all together. Time for a new one. Doesn't need to be coded.

You need to have the ignition control module checked (It's inside the distributor)

cycle key to the on position but dont try and start engine, do this 5 or 6 times then try to start

If it is a 3.8 engine change the crank sensor,they go bad on the 3.8 engines.

If the engine won't fire up, but your starter turns over, you may want to check your timing unless you have a check engine light on. If the CEL light is on, have the codes scanned.

If the engine won't turn over with the starter or it clicks, have your battery tested at autozone or advanced auto parts. Replace the battery if it is bad. Else, have your starter tested.

If the engine still won't turn over and the battery and starter are tested fine, you may have a blown fuse, bad ignition switch, or a failed relay.

If the engine fires up but randomly dies and starts back up, you either have a failed sensor, failing fuel pump, clogged fuel filter, bad plugs or wires, or a failing ECU.

I’m happy to help further over the phone at https://www.6ya.com/expert/jeremy_69f3cc28d95bf514

ignition system is the problem. need to check or replace igniter(ignition coil).

are you sure you getting fuel even though you have new fuel filter, check all fuses under the dash to fuel pump and relay under the hood, are you getting sparks? check rotor, cap, coil...make sure you getting 2 important items, gas and fuel to the engine. hope that help some

sounds like you have a good battery, get the car started put a voltmeter to wire connected to the back of your alternator. if you have at least 13.25 volts you have a good unit if any lower replace the alternator
the click sound you are hearing comes from your relay it is getting low voltage from the battery. because the battery has no juice caused by a bad alternator


hope to help shack

check alternator at auto parts also have battery tested.