'I have a vague recollection' is correct and usable in written English.
You can use it to describe a fuzzy memory of something. For example, "I have a vague recollection of going to that restaurant a few years ago, but I can't remember it very well."
And I have a vague recollection of the subway.
I mean, I have a vague recollection of what I said, but what it looked like, I don't know.
I have a vague recollection of feeling like I was floating while walking through Times Square and watching some kind of Japanese samurai movie with him.
I have a vague recollection of K. Livingstone talking about devolving some powers to a very local level but nothing more.
And I have a vague recollection of parsing lines in Father Duffy's class — something about a long-long followed by a long-short-short.
Or, as Farah Murad, a 20-year-old student at the German University in Cairo, said of the attacks, "I have a vague recollection, but it was so long ago".
I had a vague recollection that I also liked the Nets, the other team in the New York metropolitan region.
I had a vague recollection that the fatty acids in fish promoted fetal brain development — but also that some fish contained pollutants like mercury and PCB's.
I went to the reading so drunk on Nyquil that I couldn't remember any of it afterwards, although I had a vague recollection that I'd thrown up on the table.
"I've a vague recollection of Brian Clough having a big say in Frank Clark getting the Forest job, but nothing else springs to mind …" Towards the end of this 1995 autobiography, Clough muses that "in some ways I would have liked Ronnie Fenton to take over when I retired", but the board at Forest opted for Clark, whose name Clough had given when asked about his successor years earlier.
I had a vague recollection of Director Singh from the comic books, but I had to do a little research to figure out exactly who he was.
