I was told the fuel pumps for the october 1990 ranger and november 1988 ranger do not have the same part number. Is this true? They look the same to the naked eye.If they are not the same what is pressure each one puts out and what are any other differences they might have? What controls the fuel pressure regulator? It has a hose hooked to it and i removed it and has a small amount of fuel spewing out where the hose connects. Is that normal.

 

The 1998 fuel pressures runs higher than a 1990, 65 (55 for a flexfuel) versus 35. Also the 1998 is a returnless system, so that pump assembly will not work in a 1990 or vice versus.

The fuel pressure regulator is modulated by engine vacuum, if you have fuel coming out of the vacuum port then the regulator is ruptured and should be replaced.

 

I believer the question was about 1988 and 1990 rangers. The 1988 should also have a frame rail mounted fuel pump, which makes the in tank unit a pick up pump and not hight pressure pump. The two may look alike, but the difference is about 80 psi. The 1990 will not run on the 1988 pump, but the 1988 might run on the 1990 pump. It will just overwork the pressure regulator and frame pump.
The other post was correct on the fuel pressure regulator being faulty. If fuel comes out of the vacuum line going to it, you need to replace it and change oil, as the fuel is being sucked into the intake and possibly by the rings (flooding) and winding up in the crankcase.

 

Senior moment! My brain saw 1998, sorry for the confusion.

 

I wish I had less of those. Now I lay my wallet out so I can see my drivers license when I get up.