AN MD80 FLC WAS TAKEN OFF THE APCH AFTER LOSING SEPARATION WITH THE PRECEDING ACFT AT LGA.

Narrative

WHILE ON XWIND VECTOR TO LDA RWY 22 AT LGA; CAPT; ACTING AS PNF; REQUESTED FROM APCH CTL THE TYPE OF ACFT THAT WE WERE FOLLOWING. INTERVAL WAS CLOSING ON TCASII. APCH DID NOT RESPOND IMMEDIATELY BUT DID TELL THE ACFT AHEAD OF US WHAT HIS INTERVAL WAS. AS SECOND REQUEST YIELDED THAT WE WERE FOLLOWING A B737 AND THAT WE WERE TO SLOW TO 170 KTS; DSND TO 2000 FT AND TURN TO 150 DEGS TO INTERCEPT THE LDA. THIS CAUSED US TO CLOSE THE ACFT AHEAD TO AN EVEN CLOSER INTERVAL AS THAT PLANE WAS ALREADY SLOWING TO FINAL APCH SPD. WE FLEW THROUGH THE LDA TO THE E TO TRY TO OPEN THE SPACING TO MORE THAN 2 MI WHEN CLRED FOR THE APCH. THE CTLR GAVE US A HDG OF 270 DEGS TO RETURN TO THE LDA. I REQUESTED TO HOLD THAT HDG TO INTERCEPT THE LOC FOR RWY 22 FOR SPACING BUT THE CTLR WANTED US TO TURN L TO THE LDA. I SAID WE WERE UNABLE DUE TO SPACING. THE CTLR WAS UNSURE OF MY INTENT TO INTERCEPT THE ILS RWY 22 LOC AND GAVE US A CONTINUE ON HDG 270 DEGS; MAINTAIN 2000 FT FOR VECTORS AROUND FOR ANOTHER APCH. TALKING TO ANOTHER PLT IN OPS AFTER LNDG REVEALED THAT OUR COURSE OF ACTION WAS THE SAFEST IN THAT THE ACFT; PRIOR TO OUR INTERVAL; EXITED THE RWY LATE AND INDUCED THE B737 AHEAD OF US TO SLOW EVEN FURTHER ON FINAL WHICH WOULD HAVE SHORTENED OUR OVERTAKE INTERVAL EVEN FURTHER.