04 4.7l with 219k think i have alternator issues. Thought it was the battery as i went on a business trip for a week, got back home went to crank it and the famous click click click. Battery was under warranty took it to napa they tested it said it was just low they charged it and i brought it back installed and got her running. Here is where i think i have a problem, i let it run for about 15 minutes to warm up it was rather warm here in South Carolina over the weekend. I had to go to my shed and get something so i turned it off. when i returned i cranked it back up and now when it cranks if the tack gets below 1000 rpms the engine shuts off. After a couple of times of doing this not wanting to kill the battery it still does this when cranking and giving it gas it will run but when i take my foot off the pedal it dies. Anybody got any ideas of what could be causing this?? Could it be the alternator??

I'd start with this tool from Amazon


Amazon.com: Battery Tester FOXWELL BT705 Automotive 100-2000 CCA Battery Load Tester, 12V 24V Car Cranking and Charging System Test Scan Tool Digital Battery Analyzer for Cars and Heavy Duty Trucks: Automotive

The Foxwell tool (Car Cranking and Charging System Test Scan Tool Digital Battery Analyzer for Cars and Heavy Duty Trucks: Automotive) will tell you that the alternator is "good" (or bad) and what the charging rate is, as well as if the battery is "good" (or bad).

If you can get the truck to most any auto part store they can test it for you for free. That way you don't have to buy that tool unless you want to. Just get it started, and drive over to a store, keep it running and they should be able to do a load test on the battery and charging system. Its not 100 percent accurate but its pretty good

That was my first thought but when i go to put it into gear it shuts off.....

simple test....start the vehicle. pull the battery off. if it dies its the alt. its incredibly easy to replace.

Definitely not an incredibly easy replacement....maybe on the v6 where its at the top, but on the v8 it is buried under everything else.

Use a meter... measure at battery while engine idles, you should have ~ 14VDC. If only 12VDC or lower, the alternator is not working properly.

The problem with checking is as soon as i crank it up if i let off the gas the engine dies. it will only run if i keep my foot on the throttle..
Could this be something else besides alternator????

I'm guessing it could possibly be something going on with the throttle body, in older models vehicles the TPS...Throttle Position Sensor is a separate/replaceable part attached to the throttle body and if bad can do what your's is doing plus other issues, but on the 4th Gens 4Runners the TPS is integrated into the throttle body and can't be replaced.

I have never had to test one but here's a link that may help you get started on how to test the sensor to see if it's bad, you may have to do more research to be able to actually test it properly, such as the values mentioned to know if it's within the correct range and the type of sensor it is.

Symptoms of a Bad or Failing Throttle Position Sensor | YourMechanic Advice

I suspect a bad battery coupled with bad NAPA testing, it is possible. I have had batterries heat up and the plates touch. So If possible check voltage, find a ground inside the car, ground one side of the meter and CAREFULLY test the cigarette lighter voltage, I believe it is straight battery juice. Be careful not to short out the probe, protect it with tape if you have to.