Truck runs horrible after p7100 install.

[guntruck]

I just had a mechanic who specializes in cummins motors in heavy equipment install my used p7100 pump. The pump came from Brad at Poncies diesel in california who was referred to me by Piers. I got a pump off a 96 wich was a 180 replacing my 160, Brad asked me if I wanted him to slide the plate in the pump for more HP which I agreed to, he said it was free of charge. Curly (my diesel) mechanic got the truck started and adjusted the idle which was still a hare high but ran excellent, he said let her warm up then take it for a spin, he left. When it was at 180 degrees I took it out. It was very responsive and quite a bit of get up and go, when I finally stomped it to the floor it popped and started smoking white really bad, it sounds as if its missing it pops and backfires and runs horribly. Before I stomped it it was no smoke only when I hit it a little bit it would puff black but after I hit it hard then all went to hell, It now idles smoking white but when you touch the pedal it starts missing and popping and smoking white really bad. If anyone can help please help me please I am stuck in the mud, the mechanic said it sounds as if its overfueled and that the 180 pump might me dumping too much fuel in which cant be fixed or did the plate being slid forward screw things up . PLEASE TELL ME THE PUMPO DOESNT HAVE TO COME OFF AGAIN IT WAS A & HOUR JOB THAT COST ME LOOT. I can call anyone if yyou can help me thanks in advance.