My del originally came with a d but a b was swapped in. Ever since the b20 was swapped in it never ran right. At first it was running sluggish when full throttled. Now my bro's friend changed up some wiring and it doesnt run sluggish anymore, but it is running rich and only get 125 mile to the tank. I'm not sure what to do and which wire was changed. Any help at this time would be greatful.