i recently put did a b18c5 swap into my teg. I was having some problems as well. It was running really rough and just horrible. I did a few things that helped me to figure out my problems. The biggest help was just checking the CEL codes. Im not sure if yours is throwing a CEL light or not, but if it is, definately check into that. Mine ended up being something very simple. Just a coolant sensor and i cleaned out the IACV. Anyways hope ya figure it out.