I just purchased a 1980 rx7.

Here's the history, when I bought it the guy said he blew the first engine and it was replaced. The starter was not on it and he said it would run if I put the starter on so i did. sure enough it did but now i'm finding some problems and would like some advice.

First off it has been sitting for 2 years. It is standard with a header pipe. when we started it we got a really loud backfire but after that it idles fairly normal.

heres the problems: When I first start it I get a lot of white smoke then it settles down and just a little comes out during idle. It idles about 1000 rpms when i start it it also lopes for about 10 seconds or more then goes to idle. when i step on the gas hard it dies but if i feather the gas it accelerates. When we took it for a spin there was a fair amount of black smoke coming out and it doesn't sem to have very much power. after we got back and shut off the car I tried starting it again and it would not start, no juice. I left it for the night and tried starting it in the morning and it fired up it also starts if we boost it. My friend came over to look at it and he said it doesn't look like the coolent was circulating.
also when I the choke does not stayt out when pulled at any temp it just slides right back but it does work cause if i hold it out the engine revs high.

any advice would be appreciated
Thanks