1993 Mazda MX6 Air Fuel Mixture

I have just finished rebuilding this 2.5L v6 and am at the stage of getting it started. The timing is set at 10 degrees btdc. I have fuel getting to the plugs and have plenty of spark. With the throttle wide open the engine cranks over until the mixture leans out and tries to start. It sputters for a few seconds and then the fuel mixture becomes too rich again. I have minimum vaccumn (about 1 lbs.) To my fuel pressure regulator. When I purchased the vehicle, the owner had removed all the smog equipment: egr valve, vaccumn lines, etc. I need to get the car up and running. Any suggestions would help.