These functions work seperatly, so yes its possible.
What iv found about how i use functions it goes something like this for example:
Fi does its thing then messages it to Ne, Ne does its thing with the info that it got from Fi and messages it to Ti, then Ti processes the info and info comes to conscious. If some Ti for example fails to process the info, it sends it back to bottom functions and this whole process can happen multiple times in so little time that its impossible to see that it went over meny times. If something is really hard for you to process it might loop around for really long time taking brakes at time if you just cant find new info to brake the loop. Lower functions work more unconsciously and not that often unless situation really needs them, while with stronger functions the processing can be quite conscious, especially after few loops. So if you got really sucky Si, it might not take action(atleast enything conscious or big) and wont give you ansver(usually) on situation where you arent used of using it.
If i would be in situation where i need to use Te, ill use it instead of Fi, but the process would work the same way, maybe bit easier tho, because Te is more like Ti.
If i use my Fi in situation where i need to extravert allso, the Fi looks more like Fe, even tho im not really using Fe.
This is just something that i have noticed about myself, not something that i have read about somewhere