99 Eclipse needs help starting

ok well i turn my key and it wants to turn over but nothing, do it again and the same thing, but then the 3rd time it starts but it has low rpms and will almost stall out, but if i let it sit there and heat up it will run fine, but if i sit there and press down on the gas its will drop in rpms and then go back up, and then will drop again and all most stall out, so the only way i can get the car to move is to let sit there and chug till it heat up and then its fine, i have replaced almost all the sensors but the crankshaft any ideas would be helpfull before i go out and buy a new car over this
thanks guys

well i found out i dont think its a sensor it has somethign to do with my breaks, cause if i pump them a bit the car starts fine and theres no ruff idle, so ill post more when i get it fixed

how about vacuum lines? have you checked any of those out? i don't see how the brakes would cause the engine to run any differently at all but maybe someone has some other input.

yeah its a vacuum line to my break boster, now i just need to find where that is, well the break boster is what i was told, i know nothing about cars and trying to learn how to do everything my self. any info would be great

the brake booster is part of the master brake cylinder. it also includes the brake fluid resivior and the brake lines run into it. it's that whole big part of things.

ok that sould be fun :)