Well I am not the pressure king unless the pressure the wife generates from time to time is factored in. Actually she is a great wife yet there are some simular typical traits amongst all her specis that they share in common. For example . I have been the reciepient of several verbal reminders that I was negligent at taking a pill I am to take with supper. Each reminder seems more insistant. So I better go take the pill.

Back to your injector. What would be more concerning than just the the injector opening earlier. Is the possibility of more actual fuel being delivered from that element.

I assume and it is always dangerous that once an injector opens the fuel in the element is used until the pressure in the element drops below the close off pressure of the injector. If the injector is opening earlier and closing off later. This is factually what an injector with a signifigant lower pop pressure might do in my opinion.

I guess with a little effort I could still do all the math. But it would be a pain. Generally though any issue you have if from this source would be caused by the increased volume of fuel in combination with the earlier start of injection I suspect. Additional fuel being more problamatic than the timing shift perhaps or a major contributor to it. .

Could it cause a rattle or whatever is beyond an absolute answer by me. It might. What is certain. If it is as low popping off as you quote it is certainly not ideal.

I would also expect that cylinder to be running somewhat hotter. Simply because of the slight timing advance combined with more fuel being used. . The reduced injector spray pressure resulting may be detrimental to the actual spray pattern as well.

Things I do not know but might speculate on. Does a sub standard pop off injector open wider? If so does it dump the elements fuel quicker and shuts off earlier. If this were so it would tend to further increase the timing advance as more fuel would be processed before the mid point of injection.

Some other member out there will know far more than me I believe. They hopefully will post. The more we learn in this area the better.