As many of you know, the actual flow rate of MP+40 injectors can vary by quite a bit. In the past, I had many NOS +40 injectors batched. They ranged in flow from 520-560cc/minute. They were NOT batched together whatsoever by MP, so you could have a set flow as much as 40cc/minute difference. Some of our vendors do batch them, so depending on where you buy from, you may or may not have a balanced set. This is not really new news to many.
What is sort of surprising at least to me, is I also just had had a set of 4) 5277895 current TII-TIV injectors cleaned and refurbished. I always send at least one extra injector to Mr. Injector in case Bill finds any with external leaks. If leaking externally, they cannot be cost effectively rebuilt. I was always under the impression that OEM injectors that came out of the same vehicle would be a batched set and flow very close to each other. What I didn't realize is that the same exact part # (in this case 5277895) after refurbishing, can flow different amounts. So after sending in 6) 5277985 injectors, 4) flow 360CC/minute, and two flow 376/CC minute.
So in a nutshell, not only do the +40's vary by a lot, the 5277895 injectors (and probably many more) can vary too. Unknowingly placing the least flowing injector in the best flowing cylinder and you could get a stacking effect going on. So the moral of this story is don't assume a given injector is going to flow x amount, unless it has been flowbenched.
Todd