Pull the starter motor so you can see the flywheel. Make a chalk mark on the flywheel. Have someone turn the engine over by hand while you watch the flywheel turn one revolution. Look at the gear teeth and watch up in there for flexing and cracks and see that the bolts are all tight.
if the starter is bad you will hear one single click, if the flywheel is bad it will sound like a heard of daemons are trying to exit from under your vehicle. if its your flywheel you will know what i mean by the comparison
Remove the starter and inspect the ring gear on the flywheel.
Its probably a bad flywheel
if its manual bad clutch if automatic bad turbineconverter go to a garage as soon as possible before the transmission or flywheel brake because that's exspensive
bad alternator/voltage regualtor
bad ground wire or not enough ground
Bad coil? Bad rotor? Bad distributor cap?
it is probably a bad ignition module or computer
You need to remove the starter and look at the teeth on both parts.
I would suspect the map sensor is bad.
Bad Ring gear (flywheel)?
Bad starter, bad flywheel/ring gear, bad starter/flywheel alignment.