I had a shop scan my 03 powerstroke recently and I was told that #1 injector misfiring, #2 and #7 had coded. I replaced #1, buttoned everything up, cranked the truck over and it fired, ran rough for about 10-15 seconds, coughed a bit and quit. Now it won't fire. There's no smoke when cranking, and it turns over fine, just won't fire. I've cycled the fuel pump a dozen times just in case it lost its prime, but could it be the HPOP, or should I be cranking it longer? I only cranked 3 times, about 10-15 seconds each time.