Update about a set of used Cav BB injectors that 77250Ford was kind enough to loan me for testing.......ironically, while I was putting my notes together on the injector test, 77250Ford sent me this link:
6.9L%20Injectors

I would like to give credit to Shimon Mor for his time and effort on the article and I hope he and others see my reference to his article as "additional information" and is in no way being negative to his article..............

The very first thing that I observed was the copper sealing washers stuck hard onto the nozzle and nozzle cap and there was a lot of carbon build up between the washer and the nozzle.....so, I just dropped all still assembled injectors into the cleaner for 24 hours........now a few washers come off with my fingers.....most I had to slowly twist off with pliers........when I examined the washers, I found most of them distorted from the injector being over tighten during installation and both sides of the washer showed heavy signs of the port in the head and the nozzle cap not being cleaned when installed..............

Next, I removed the nozzle caps and found a large amount of carbon material on the inside of the nozzle caps.............when I looked at the sealing surface of the nozzle and nozzle holder, it was easy to see the OEM design is "crap"..........this means the shoulder of the nozzle and the inside of the nozzle cap Must be absolutely clean to seal.................

Next, I looked at the threads inside the nozzle cap and on the injector body...................every single one showed signs of bad threads in the nozzle caps and most of the injector bodies...................I determined all eight injectors as "trash" on this single point..............If I can not trust the threads in order to properly torque the nozzle cap in order to get the best seal I can from the "crappy" OEM design......its useless....................

Next, I checked the "edge filter"........this is found inside the injector body (its a fluted spiral piece of metal, that its shape and design breaks large droplets into smaller ones....mostly for water) they "felt very restricted" and I would have several "soaking" and blowing them out..............

Next, I removed the pintles from the nozzles and did my first cleaning/polishing of them.....the pintles showed heavy wear marks along the side (looks like straight shinny lines drawn on them) Warning sign.............

Next, I sprayed then heavily with WD40.........after carefully installing the pintle into the nozzle is the First Test on them.............holding just the very tip of the spring end of the pintle and with the nozzle pointed straight up.......I take my fingers and spin the nozzle "just like a top".........I am both "feeling" how it spins and if it Stops at the same place on several spins...............all eight nozzle/pintles Failed the test...................................some did not "feel good" which may mean they need more cleaning........................some Stopped at the same place in rotation......most likely you can not fix this and I "trash them"..............

Next, I held the nozzle and pintle at about a 60° angle and pulled the pintle out to its max range and "just let go of it"...............it Must "freely fall to seat repeatably"..............all eight failed even after several times of cleaning them.........................

Next, knowing that all injectors were going Fail the drip test badly, I just wanted to get a ruff idea of what they were popping off at.................they ranged from about 800 to about 1200 PSI....................

Note: on the third injector that when I was torquing the nozzle cap .......it cracked in half in the threads.............................

My personal opinion: this style injector (Cav BB) is a "throw away when maintenance is required" and I will start with a new set of injectors.........................

crossbones

 

As I posted very early in this thread, just buy new or reman injectors, they are inexpensive and not worth the bother for the average person- but if you like to tinker, you can have a tester to at least confirm even pressures and leakages etc, or rebuild your own if you can find the parts. FWIW

 

I hope you at least enjoyed you time fooling with them. Just about anyone here could've told you they are junk.

 

If you buy reman injectors what assurance do you have that they didn't take a crappy injector like crossbones was describing and rebuild and sell it. For as cheap as they are, I think new is the only way to go. Now,as to which one to get,that's another story. Any recommendations? Do I have to replace the IP also?

 

Buy new, like said they are inexpensive! I like to tinker, so when I pulled my originals, I just bought a set of remans to stick in, they run great and even, so I guess I did OK.
Since then I built a tester, and was able to buy "new" stanadyne tip assemblies for 6 bucks each, so I have rebuilt my originals for next time.

With my experiance to date I would say the most important maintenance you can do next to oil and filter changes is to keep the injectors in good shape with pop off pressures in the recommended ranges. As they weaken the timing changes, so if you just change injectors, plan on rechecking your timing. I changed out my IP only because I didn't figure after 240,000km it owed me anything, and I was supprized at how much more power the truck seamed to have when I changed it out. (I did the injectors several thousand km before the pump, but again I didn' t really mess with the timing on the original pump either). So long story short, you don't have to change the IP with the injectors, but it is recommended- if the injectors are worn, so is the IP!