W-H-I-C-H fuel pump?!?

[Trevorrudai]

Hey all I've been coming here for answers to my 2.9 questions for quite some time and just today finally made an acct! Anyways, I am nearly 100% confident in the fact that I have a weak fuel pump causing my problems, however I don't have a test gauge and therefore I don't have any knowledge if there is any other way to determine which of my fuel pumps may be the culprit? Is that going to be the only way to determine which one it might be?! TIA!!

 

[RonD]

Welcome to TRS

Symptoms of lower fuel pressure would be losing power at highway speeds or going up hills, situations that have highest fuel demands for the computer/engine
And Lean codes would come up because of this

But dirty fuel filter would also cause similar symptoms
And Fuel Pressure regulator(FPR) on the engine can also cause this lower pressure

Fuel pressure gauge is basically the same as a tire pressure gauge, same fitting, schrader valve
Should run 30-35psi with engine running, 40-45 with Vacuum line on FPR unplugged


look here: https://www.therangerstation.com/tech_library/OBD_I.shtml

In 1986 your OBD connector should be on passenger side of engine bay near firewall
Looks like second drawing down in above link

Fuel pump slot is labelled in that drawing
If you put a GROUNDED wire in that slot the fuel pump will run full time when key is on, instead of just for 2 seconds
Doesn't hurt anything

You can then unhook the fuel line coming from the gas tank at the high pressure pump(in the frame rail)
Put a container under it and turn on the key, run it for 30 seconds to see how much fuel comes out
Fuel pumps are rated in GPH(gallons per hour), well newer ones are rated in Liters per hour(LPH), lol

 

[Trevorrudai]

Hey Ron, unfortunately the owner before me managed to remove/break/lose the metal conductors inside the fuse box that my OBD fuse goes into for bridging power. So, no OBD codes for me ever at any point. However the first suggestion should work fine as long as I do not have to drop my fuel tank. I am removing the bed for access instead. Why? Again, the moronic owner before me WELDED the fuel tank skid plate/protector.

 

[RonD]

You want to slide back or tilt up the bed on Rangers to access fuel tank in any case, dropping the tank is OK IF.......you have a lift and the transmission jack, like in a shop setting
They are way to hard to reinstall while laying on your back while trying to hook back up the hoses and wires

 

[Trevorrudai]

Okay so I'm here ready to do my pressure test however Ford as we all know makes these quick connects that I simply cannot find any sort of adapter that will hook up to my quarter inch fuel pressure tester

 

[Trevorrudai]

I disconnected the fuel line behind the inline fuel filter that way I can get a accurate reading on exactly how much pressure the fuel pump from the tank is sending

 

[RonD]

Should be 6-9psi