i have wired mpfi, and now my car is only running on cylinder 1 and 4, im not sure why 2,3 arent fireing, i have new wires, plugs, any ideas?

 

The only things those cylinders have in common are timing (because they move together) and the fact that they are adjacent. You could have a HG blown across the two cylinders. Try a compression test. If compression is ok then verify that you are getting spark and if those injectors are firing.