Here is the deal just over the last 10 or so months (l was on deployment) My Impala would ''sometimes'' start when l turned her over. Other times...well a good number of times not. l have to give it gas and keep it above 2000 rpm for a few seconds. If l took my foot off then it would cut the engine off. And l would have to restart the process. (It is embarrassing when in a crowded parking lot) l took her to various places and got it checked battery, alternator, etc. But then l actually took it to the Chevy dealer and they said it was either the mass air flow sensor was clogged or chang the air filter. Well l changed the air filter and it worked-ish. They charged and astronomical price for this and even to change the air filter. So needless to say l filed a complaint through the BBB. So, here is the other thing, it seems to start fine-ish in the cold rather than in the summer or rain. Strange. Very strange. So if anyone has any ideas or anything please feel free to help. Your suggestions and comments are greatly appreciated.

Sounds like your starter is starting to die.
Make sure that your battery is good.
And if you're losing power it is probably the alternator.

Have you tried the fuel filter or take it to autozone for a free check up

The chevy dealer believes your fuel/air mixture is too rich in fuel and is lacking air for combustion. Ask around and find a real mechanic. A simple adjustment to your carburetor may be all that is needed to get your car to start and run properly.

well it sounds like a mass air flow sensor .. when the air changes do to cold or rainy conditions it affected how the engine run.. spend about $50 bucks at you local used parts location and pick one up .. here in alabama you can go to montgomery and a place called ''pull a part'' you can get one for around $10 bucks you have to pull it yourself .. but hey it is cheap..