Updating fuel pump, 'Bronco 2 '87 to '90

[mic98xlt]

I need to replace my low pressure fuel pump that is located inside the fuel tank on my '87 Bronco 2. I'm aware that on the '87's there are two fuel pumps with the one in the fuel tank being the low pressure, and the other one (high pressure) on the rail under the drivers seat. Since I have to change the fuel tank pump, I was thinking of changing to the later '89-'90 fuel pump that basically combines both pumps (high and low pressure) into one unit inside the fuel tank. I can handle the plumbing to eliminate the high pressure inline pump under the drivers seat but I have an question. I think the connector is the same for the '87 and '90 with both having four wires. Will the fuel gauge read correctly or not at all when it sends a signal to the dash fuel gauge from the updated fuel pump which contains the fuel gauge sender signal? I read somewhere the fuel gauge may not work but I'm not sure if that is correct. Any and all help would be appreciated regarding pumps swap or fuel gauge.

 

[RonD]

No, fuel gauge won't read correctly
Empty-Full
----73-10 Ohms ---'pre-'89 Fords
----16-158 Ohms---'89 and up Fords

So opposite and wider range on the newer one.

 

[mic98xlt]

Thanks RonD, great info. That makes complete sense why the fuel gauge wouldn't read correctly. I would love to have the dependability of the later single tank fuel pump but for me working fuel gauge is very important. I wonder how feasible it would be to possible swap the old fuel sender unit part ('87) to fit the newer fuel pump housing body ('90)?

 

[RonD]

What you may be able to do is to use a universal 40psi in tank fuel pump, and leave current in tank sender alone.

You would need to pull the current assembly out and see what will work but shouldn't be too hard to do the retro fit.

Example of universal pump here: http://www.summitracing.com/int/parts/aei-11165/overview/


You may even be able to set it up as a siphon feed from tank to high pressure pump in fuel rail.
This was used for..........60 years for mechanical fuel pumps on the block and carbs.
So get rid of the in tank pump altogether.

Although it would be a pain if you lost prime, same as it was for those 60 years, lol

 

[mic98xlt]

RonD, I like the idea of the universal pump but it's just a little pricey yet I still may consider it. You definitely have given me some food for thought on this pump update.

 

[RonD]

Fair enough, Motorcraft replacement is more though.

Airtex makes less expensive pumps, if possible see if local parts store has a 1990-1997 Ranger fuel pump assembly, if so go down and take a look at it, get pictures, maybe you can retro-fit that pump to your assembly.
Or maybe hit a wrecking yard and get a motorcraft pump, needs to be '97 or older, '98 was the start of the 65psi pumps with no return line

 

[mic98xlt]

RonD, I really like your way of thinking! Yes, starting with the '87 assembly is a better idea for the retrofit. I'm going to cut open an access door panel to avoid dropping the gas tank thereby making it easier to get to the tank fuel pump. This would also aid me if I put in a less expensive pump like Airtex (budget friendly) should it need changing in the near future.