fuel pumps

In 1984-1986 there were some versions that had a low-pressure in-tank fuel pump AND a high-pressure in-line pump. VIN code M with a carb should be an engine-mounted mechanical pump. VIN code M with TBI should have an in-tank pump only. VIN code F with CFI would have two pumps. If yours has it, it should be plainly visible. Just follow the lines from the tank. It should be 4-6 inches long and cylinder shaped with the inlet and outlet located on the ends. Check out: http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c1528004e110 The wire from the relay SHOULDN'T get hot unless there is a problem. If you suspect an issue, use a voltmeter to check the wire. If the wire gets hot, that indicates too much power going through a wire that's probably not big enough to handle it (either poor wiring, faulty wire, or a short somewhere). There was a Severe Service Package (SSP) Mustang available from late 1982 to 1993. The 1985 was available with either a VIN code M, 5.0L with 4Bbl carb (210hp/270ft-lbs) or a VIN code F, 5.0L Central Fuel Injection (CFI) (180hp/260ft-lbs). The carb version should have an engine mounted mechanical fuel pump and the CFI normally would be a two-pump version, but it may only have one for greater reliability, although I can't find anything to confirm that theory. Check: http://www.sspmustang.org/