High Flow Fuel Pumps

[ajonesnv]

Can anyone explain how there would be a benefit to having a high flow fuel pump, assuming the truck engine is stock and it is driven normal.

The ECU decides the amount of fuel and assuming the standard pump is delivering the proper amount of fuel, I don't see a need for one.

Anyone care to elaborate on the other side of the argument?

My Fuel pump is on its last leg, so I am looking around at pump options, hence my question.

 

[JohnMc]

It's not needed at all.

All stock pumps can deliver comfortably more fuel than the engine will ever need, even at WOT/high rpm. The fuel pressure regulator holds back the correct amount of pressure, and all the excess fuel just flows right back to the tank.

If you put a higher volume pump on, the result will just be more fuel returning back to the tank. You only need that when you've modified the motor to make a lot more HP, and you've (more than) used up the built in extra capacity in the stock pump, and the engine is not getting enough fuel at peak power levels.

 

[98OzarksRunner]

The fuel system is (according to the manual) a return-type system, meaning that any fuel that is not needed is returned to the tank by the regulator. Unless you have a supercharger with larger injectors, a high-volume pump will simply mean more fuel is returned to the tank. In high-performance applications that is not desired since the returned fuel heats the fuel in the tank and hotter fuel is less dense, reducing power. In short, there is no benefit to a high-volume pump on any vehicle unless the engine performance has been increased to NEED more fuel.

 

[csp]

High flow could actually be detrimental in theory. If the return flow is greater than the return line is sized to handle you could introduce a rich running condition and higher than normal fuel pressures.

 

[BrianSD_42]

What argument lol?

Who told you to consider a high flow fuel pump for your 4runner?


:bat:

 

[98OzarksRunner]

High flow could actually be detrimental in theory. If the return flow is greater than the return line is sized to handle you could introduce a rich running condition and higher than normal fuel pressures.

This is true. I ran dual 255 LPH pumps on my 65 Mustang and the regulator and return line couldn't return enough fuel to keep the pressure correct at normal loads (which made it run rich). I had to put the 2nd pump on a Hobbs switch so it only kicked on when boost hit 2 lbs.

 

[ajonesnv]

What argument lol?

Who told you to consider a high flow fuel pump for your 4runner?


:bat:

Nothing I read specific to the 4Runner, but other forums claimed out landish gains.

I figured what had been posted here, just wanted to confirm my thought process due to not knowing much about the system, just knowing theory.

Thanks!!!!

 

[ajonesnv]

Well, the new pump is in. What a PIA! Thank goodness I had a trans jack in the garage.

 

[csp]

You dropped the tank?

Did you know there's an access panel under the drivers side rear seat?

 

[ajonesnv]

The access panel is to the electrical harness only...dropping the tank is required.

 

[JayRolla]

High pressure fuel pumps can also overrun stock fuel pressure regulators causing major rich issues at all rpms fuel maps, ect. Like stated only needed if you are out of fuel from added air flow from forced induction.

 

[ajonesnv]

High pressure fuel pumps can also overrun stock fuel pressure regulators causing major rich issues at all rpms fuel maps, ect. Like stated only needed if you are out of fuel from added air flow from forced induction.

I did go with a stock pressured unit.