This morning, I stopped at the gas station and when I fired my engine pulled away & it was sputtering and smoking bad. It is a rebuilt 6cyl, 2,000 miles. Has been running perfect until this morning. When I installed the rebuilt motor I added a DUI ignition, Weber carb, no emmsions stuff, etc. Doesn't seem to me to be fuel problem, maybe like it's misfireing? The smoke is white, definately not blue? Any ideas????

Thanks