One Cylinder Cuts Out At High RPMs

[7.3early99F550]

Hello all. First post on this forum. Would like to start off saying that this site has been the best in my opinion for everyone. Great info and people are what make this site great.

I have been searching for a few weeks(going on months) on this and other powerstroke forums for a fix on this problem.

I have an early 99 with a miss at or near full throttle when the rpms are around 2400 and climbing, if it still can. It idles fine, accelerates fine up to red line if at 75% or less throttle. If you go any deeper on the fuel pedal, one cylinder noticeably cuts out.

Another thing to note. This F550 has a 6 speed w/ 4.88 rear end. When it idles for more than 10 seconds (at a stop light or sign) and do a Low gear launch, it revs without a miss up to 3k rpm in every gear up to 2nd gear. L to 1st to 2nd. This revving and gear changes from a stop can happen in as little as 6 seconds. It leaves 2nd gear at 3k, 3rd is a little steeper and has a 2k rpm entrance and takes alot longer to rev up. This gear is the one that is really starting to load the engine during hard acceleration. That is when the miss starts.

I have already done every test for pressures, sensors, contribution, multiple colored cps (currently the grey one), etc etc etc. All are passing values as if it was a new engine. The only thing I haven't done is manually turned off each injector at high rpm and throttle conditions using a homemade injector cut out box.

My question is, what other options do I have for testing for a faulty injector? Should I send all injectors in to a reputable rebuilder for flow and pattern testing? Don't really want to dump $$$ into getting all remans back if only one needs to be fixed.