help '95 325i won't start
 

When the cold weather started, my car began acting strangely. back in october one morning I went to start it and it was chugging and shaking and blowing blue exhaust. I waited a day or two and tried again, same result. so I said the heck with it and let it sit for a couple of weeks. One day I was feeling lucky and went to start it up and bingo! Dang thing started right up!
Ran great until the weather got colder in december. Drove it one night, ran great. two days later I moved it to a different parking spot, started ok and everything. Then about 4 days later I went to start it on a cold frosty morning and it cranked over but wouldn't catch. I took the battery to auto zone and they tested it and said it it tested good. it was at 75% charge so they charged it up and I reinstalled it.
I cranked it over in 20 second intervals on two different days. The last time I did this was today it was about 5 degrees. I cranked it over about 5 or 7 times for 10 to 20 second intervals and it sputtered for about 2 seconds here and there. The cranking just got weaker until the battery was drained. I'd appreciate any help, seems to be related to the cold weather. Thanks, Jetty Note: this car never did start without 2-3 seconds of cranking, i've had it since july. Thanks again and Thank You 3500 RPM I'm thinking fuel pump now too.