I learned first hand how important the torque sequence in when doing common rail injectors. First set I put in I had to do over. Truck ran but didn't have much power. I think your problem was the injector install.

I would follow cummin un glued's advice

 

yeah getting it right is very important on these engines. typicaly when something isnt right after any kind of repair or modification, retracing the steps will find the problem. that being said sometimes a modification will cause something that was a minor problem before to become more odvious. tests will have to be ran to determine which is the case.

 

I noted the same issue. I put new stock industrial injection injectors in my truck and I went from averaging 17 to 12 mpg. After running truck for a few thousand miles mileage came back to where it was. Not sure why it happened but i have read other posts of people complaining of the same issue and a few thousand mile later it was ok again. If its not knocking or blowing excessive smoke I wold say run it a while and see what happens.

 

yea ive been knoticing its been getting better.