Help with 84 733i

My 84 733i has been in the garage taking up space for tooo long. I had to replace the crankshaft pulley which this group helped me. But now it runs very poorly. It ran great before I replaced the pulley and after I replaced the pulley and tested it for a minute before putting the belts and fan back on. Now it seems as if the timing is " floating" i.e., run great on second, terrible the next, back fires and dies. I feel that I must have disconnected a wire or vacuum line but can now find it. Any ideas would be appreciated. Larry