Why my 2001 lumina won't crank?

Defective starter motor or no power to it. You can try tapping on the starter motor with a blunt object while holding the key in the crank position to see if it starts

i think you need a new starter. my suburban cranked really slowly as well, a new starter fixed that problem

i have the 2.7 as well. mine is in an intrepid. Car was running perfectly fine when i went into bestbuy and when i came out 5 min later i tried to start the car and it would just crank n crank. no start though. eventually it started after lots of cranking. after a couple of times of doing this in order to start the car i would get nothing from the startrer. everything had power and everything electrical worked. found out that if i went under the car and hit the starter with a hammer a couple of times it would finally crank again. but i had to do this every time i shut the car off and wanted to start it again. i loive in WI and its wintyer right now so it really sucked to do this. took it to my buds shop and pulled the starter out and dissected it and found that the (i believe they are "brushes") were ground down to next to nothing, the positive ones, do to constant cranking. was going to get a starter from junk yard for 20 befor i knew what the problem was. did some calling around and found brand new brushes for $20.00. i just got those and installed them and had a good as new starter again. lots of dust to clean out of the housing though. brake fluid and air hose works wonders for that problem. but from best buy on the car would not start without starting fluid if it was at running temp. still yet to solve that one. replaced the cam sensor, crank sensor, plugs, COP's and checked the rest of the sensors. still cant figure this out. anyone have advice let me know what i can check. fuel pump kicks in wen the key turns as well...

I would say if the car stays running after u jumped started it I would replace the battery

When you turn the key to start does the starter engage an spin the engine ? or nothing happens .
the lights and music come on but the motor will not start when I turn the key ??????? Will not start how ?
crank - no - start or no crank no start . ????????

many things will cause no start problems could have faulty ignition switch.use test light see if power going to starter if not check ignition fuse to starter.if power going to starter, more likely starter solenoid or starter faulty.if ignition fuse okay and starter and solenoid okay still no start problem could be in the ignition switch or inhibitor switch faulty.code scan for faulty theft security system which will also cause no start conditions.

Won't start or won't crank ? ?
If it won't crank you might have an engine problem such as a broken timing belt.

You have a chip on your key,Your ignition has wire that goes bad,You have to get a new ignition and key that has a new chip.

no Crank ???? try to put it in netural. possible safty switch, if no crank you will need to check the crank wire on the starter, ( The Small Wire) with a 12 volt test light, when you turn the key you should have a light. if so the starter Sol Assy has failed.... Hope this helps

do mean that the plugs are firing even though the engine is not cranking?