Any luck yet?
It is important that the battery is fully charged and
ALL connectionsfrom the battery to the starter posts are
CLEAN AND TIGHT. If not your chasing your tail.
Could be the starter
and solenoid are ok, and when you "jump it with a screw driver" , you are simply making a better connection than say a loose nut, if in fact that is the case.
If the battery is up (remember the volt reading good be good at 14+ volts under no load, yet it could still be bad under load) and
all connections are clean and tight, and you still get the same result, I would just pull the starter and replace with a rebuilt one. Easy job.
Hopefully you already have it working by now
