car starting and revving high

hello. i drive an 03 cavalier. just installed new battery a month ago. When I start my car, the temp outside may be 20 or it may be like 55. either way, the engine revs way up to 3000rpm then idles back to normal. one time the engine actually died but then after a third try the car started. i have no idea and cannot figure out why the car revs so high. anyone have this problem?

thanks

sounds like a problem with the idle air vent circuit, perhaps when you replaced your battery your car kinda "forgot" where the vent should be on start-up, I know that can happen when you replace the vent solenoid. if the problem doesn't correct itself soon then it may be the solenoid.

first check the obvious (vaccum lines, wiring harneses, etc) was there something hooked up to the battery that you forgot to put back on? i know forgetting to hook up your mass air flow sensor can have some rather adverse effects on your car. next check for any blown fuses or fried circuit breakers, mostly check the maxi-fuses under your hood. the relay center should be attached or very near one of the strut towers. if all else fails politely ask a local mechanic if (s)hes ever experienced a problem such as yours and ask him/her what they did to correct it

now i have encountered another problem...

My car will no longer start. When driving down the road at night I can see my lights dim slightly inside and out. This morning, the car wouldnt make a sound when i turned the key.

wow. that really sucks.
well did you install anything that uses juice, stereo, amp, etc?
sounds to me the reason the battery died is excess parasitic amp draw.
there are two types of parasitic amp draw

good - things that use power to retain memory such as your stereo, ECM. anything that draws power when it rolled off the assembaly line is good

bad - short circuits, stereo equiptment wired wrong so they can stay usefull even though the ignition is off

to test for parasitic amp draw you take a multimeter and disconnect the negative terminal from the battery. put the positive lead on the cable and the negative lead to the battery. make sure the ignition is off and all doors are closed no accessories on.
the draw on my vehicle is acctually pretty high at a whopping .5 amp
generaly you should see about .25 amps give or take (this depends on factory installed things, etc)
if you have draw over 1 amp or more i would lean toward short circuit, if its between .5 and 1 i would try to see if there are any accessorys that are still on.