What I don't understand is...

[helpme]

Thanks Iocovaca

That must be the reason. Thanks.

 

[Lack Thereof]

why I can't push-start my 5 speed Ranger when it has a dead battery.
Also I can't jump it off with jumper cables when the battery is dead.
I have to put a new battery in to get it to crank (and start).
Are the newer ones (OBD2) like this as well?
Thanks.

If the battery is completely flat you will not be able to push start a fuel-injected car, new or old. You need a minimal amount of juice in the battery to run the electric fuel pump, and the computer/ignition system might not work if the voltage drops much below 9v.

Yes, the alternator will function with no/dead battery, however at the low RPMs during starting it's probably not going to do anything. You'd need to get the engine spinning close to idle RPM to get enough power out of the alternator to fire the engine. If you have a decent slope or get some good momentum up it's doable, but you can't just "bump" it and have it fire without at least some juice in the battery.

 

[PlumCrazy]

A FI engine will run off the fuel sitting in the rail long enough to get the engine to turn over and turn thealt and generate enough juice to start the pump and start running. Just don't shut off for a while.

-PlumCrazy