weird starting problem

[mds04086]

Ok here it goes. I installed my system(amp,head,subs) about two weeks ago. As soon as I got in my car and started it the rpms bounce around for a second then it dies. I thought no big deal its cold after all. Well it has kept doing this and the only way to keep it going is to pump the throttle when you start the car to get it "used" to running, then it stays on. Well about two days ago I started the car and it started slower than usual. I had to stop for some reason after that to get something. I went to crank the car and the engine wouldnt even turn over. So now it has to be jumped off every time. I took it to a shop and they said it was my alternator, another shop said the alternator was fine and giving current. Whats going on? Oh and by the way my battery is only 1 month old and both shops told me it was fine.
Oh and I also put an intake and header on at the same time as system if that makes a difference.

[MorganS13]

tap your starter with a hammer before you start it and if it starts right up, theres your problem

[Maeda]

Can you leave the car over night and have it start?

Have you checked it using a multimeter?
~ check the starter motor, alternator and the battery

Try a load test on the battery. Take it to pepboys or use a load tester. That will tell you if the battery is good or not.

Try a parasitic drain test by hooking up a test light to the chassis, and the other end to the negative battery post, and if the light goes on your batteries being drained.

If its not the alternator, battery or starter it might be a wire. Trace back the wires from the battery and look at your connections. If anything is burnt looking replace it.

I know its a pain in the ass! I had my car down for 2 weeks like this.
PM for more help I guess.

[efixmer]

Make sure your battery cables are fully tight...sounds stupid, but many people neglect this area and expect current to flow throught a loose cable. Make sure the clamp is all the way down on the post and fully tight. Should not move with a forceful wiggle from your hand. Make sure the chassis to block ground is good.