What is your car doing??? Theres allot that could be going on.
1: is it even cranking over?
if no
-1a: is it clicking?
-1b: is the battery charged or do your lights come on bright
-1c: check your fuses and relays also make sure to check whether you have a good grounding point, underneath your fuse box you will see a wire going from the negative terminal of your battery to a bolt on the car, make sure that is making a good metal to metal contact.
2: it is cranking over.
if yes
-1a check all of your fuses especially your efi fuse.
-2b pull out a spark plug wire and electricute yourself for a sec to see if theres juice going to the plugs.
-2c pull out a spark plug and crank then smell to see if gas if being sprayed into cylinder
-2d check that your timing is accurate.
Do those things and come back with your results, right now your problem is to vague for us to really help you.
-Luis
Ps. The alternator will only matter once your car is running, it doesnt use the alternator to start at all, if it has a good battery it will use the juice from there until it is drained and THEN die. the alternator is only there to recharge the battery and sustain the car AFTER it has been successfully started.
