2001 alero won't start, changed battery,alternator,plugs,& fuel filter, engine turns but won't start.Any ideas?

If you are saying it takes a long time to start the engine, have you checked fuel pressure before and after cranking ?

If the security light is flashing just leave the key forward for exactly 10 minutes when it stops flashing give it a try it will work

try the alternator output voltage ,should not exceed 15v if it does then this is your cause of the misfire

I see you have changed many parts on vehicle, the only other thing that comes to mind is the timing belt. but that depends if its a four or 6 cylinder. some fours have the timing belt as to the chain. and also make sure you are getting spark from coils. but check the belt first. and make sure fuel pump is ok !! have a good day !!

Good evening, if you just pushed in on the schrader valve to see it was pushing out gas, I would seriously recommend putting a fuel pressure gauge on it, because you can be off 10-15lbs and it will not start. Let me know how it goes, and if you had any check engine lights let me know.

Check your fuel injectors, replace your fuel filter, and check your fuel pump.

For the squeel check your alternator belt.

Start with the ignition controll module, it's located under the coil pack and can be tested at most parts stores. also could be the crank or cam postion sensors.

ignition coil pack it intermitten.

also check the crank sensor and the main crank pulley, this is where the engine gets its firing orders from

you can also try pulling the fuel pump relay under the hood and put it back in. works on my 2000 alero. and yes if the security light is on, you need to turn the key on and wait about 10 min. until it stops flashing, then turn off, then start car.

when it dies out try shooting a little fuel into the throat of your throttle body or air cleaner and see if it starts back up .. if it does you have a fuel problem like clogged filter or bad pump , thanks Jerry holler if you need more.