220

I recently replaced the cobbled up fuel line on my 220.  I want to add the tractor did run out of fuel.  I put an electric fuel pump on it and new fuel filters.  I bled the fuel filters and they are full of fuel.  I was going to crack the injector lines but the nut doesn't want to turn on the steel line so I thought I would just try to roll it over and see if I get smoke.  I rolled it over and got smoke and it eventually started.  It ran rough for a bit but then smoothed out.  It runs good at an idle up to about 1/4 to 1/2 throttle then starts to run rough and alot of brown to dark brown smoke out the stack.  Pull it back down under half throttle and it clears up and runs smooth.  Is this the result of not bleeding the injectors?  Is there a good way to get the injector nuts to break loose without damaging or twisting the lines?  It has the inline Minimec pump with AC injectors.  Thanks.

Why an electric pump on a system that is easily fed by gravity ???? Just something else to go WRONG.