Weird Cold Starting problem.

[toms68cst]

My truck has a stock Rochester 4B. After it's been sitting a few days ,it blows bluish smoke and rev's up very briefly (2-3 seconds) after being started. Very soon after that, it settles down, idles normally and drives normally.

I don't know if it's related or not but in the cold weather, it started really hard and usually failed to idle down when warmed up.

I also recently disconneted my smog pump because it was causing backfiring and popping.

The smoke/Rev up is my most pressing problem now that we are getting warm weather.

Any ideas??

Thanks, Tom