i have a 2.3 L 4 cylinder ranger that recently started having battery problems(well at this point i don't know if it's a battery problem...) couple days ago it wouldn't start, i jump started it and it ran and was perfectly fine for a couple more days until today. wouldn't start- i jump started, drove for maybe 5 feet and it turned off on me again. realized that it only stays on if you rev hard, so i took it home (revving the **** out of it) cause i was close to home and our battery charger thing says it's fully charged and fine but i'm not sure what's up with it. oh also in park i revved it hard and it only limits up to 3k rpms
help and thank you!

 

The symptom you described is common to an Idle Air Control (IAC) valve. I have seen them produce a DTC code but many time they did not. As for for the battery issue, I would take to one of the parts stores and have it tested. They will do it for free and are pretty accurate.

Rod

 

Look for a vacuum leak. There are videos on different ways to do this test.