magenta only has white stripes?

Ok everything is calibrated and all prints well except magenta it has white stripes. I ran a nozzle test print and I am only missing 3 nozzles the test print has 3 bars missing on magenta only and none of them are next to each other. I went into flexi made 6 boxes 2" tall and 6" wide and manually set each box to 100% K,M,C,Y and set Lc,Lm to 25% when I ran this to the printer everything prints great except magenta it has white stripes so I am thinking the head is bad but like I said earlier on the test draw nozzle check there are only 3 bars missing I cant believe that only 3 bars would cause this big of a stripe issue. It is really killing me as we are having to print everything at 16 pass which still has stripes but not as noticable as 4 pass. I even swapped the cables between magenta and yellow (magenta prints yellow yellow prints magenta and it sprayed the same this leads me to believe its the head not the driving boards).Anyone have any idea what I can do to fix this besides a new head ( I am not 100% sure a head will fix this but pretty sure) I really need to get this fixed ASAP so whats the verdict need a new head? Like I said all colors print find so it is not a media comp issue only magenta has the stripes.

All help appreciated.

 

Sorry I am using a JV3 160S. I also have a bulk ink system so can I do a hard clean? I was told by the guy I bought the printer from that I can only run fill ink and nozzle wash because of the bulk ink system is this correct? I didnt think that 3 nozzles would cause such a massive stripe in the print. As for drawing ink through from the cap station I can do this but the cap station sucks ink well so will it reallly make a difference? The printer grabbed the vinyl and bunched it up a while back but it had 2 missing nozzles before that so I dont think that hurt it to much. I did a nozzle wash for 1 hour but it made no difference at all so I will try what you guys posted and pleas let me know about the hard wash with a bulk ink system. Oh it is a triangle bulk ink system and I am running the 3.1 firmware. I am also using Flexi 8.1 for rip design in Photoshop mostlly. I have another question when I am printing how wet should the ink look after a couple passes. Right now its fairlly dry I noticed when I run a higher res and same number of passes that it lays down a lot more ink and the bands seam to be less but the colors are to dark. So just how wet should the print be when it is actually printing or just printed that pass should it have a wet pooled up look for a little while but not dripping wet? I have linerization set but cant seem to find total ink level in Flexi.