Manual pump VS stock, does computer regulate fuel at pump?

[robcuda]

Hi guys,
Does the the computer in a 97 ram 5.9 talk at all with it's stock fuel pump regarding regulation or is it solely for power on/off with ignition?
Thanks for any input.

 

[Dana67Dart]

I'm interested in the answer too, my gut says that the pump pumps full pressure and the regulator controles the pressure to the EFI.

The computer would control the injectors, so like the AC power in your house, you have ~2000 watts available even if you only use 20 watts.

You have full throttle fuel flow and pressure avalible even if you are only at part throttle

 

[MoparLeo]

Most fuel systems now run on a loop. The pump is either on when engine is running or off when it isn't. Imagine your fuel pump was a light bulb and you turned it off and on constantly....If you want to cause something electrical to fail, just keep powering it on and off constantly. Anyway it just has one speed, on. The computer just tells the injectors ( which are just like a solenoid) when to energize and for how long.
Excess fuel just goes back to the fuel tank. Not just one way like a carburetor system.

 

[TT5.9mag]

On/off with ignition only. Absolutely no modulation by the ecu at all. Fuel pressure is controlled only by the regulator.

 

[Hellrats]

The PCM only turns on the fuel pump via the ASD relay after is has a cam and a crank signal from the sensors. It will turn on for about 2 seconds when the key is first turned on then turn right back off. This is just to keep prime in the fuel system. Fuel pressure is regulated by the pressure regulator located on the top of the pump itself. It is a return less system. There is no loop (return line) like early fuel injection systems had.

 

[robcuda]

I'm interested in the answer too, my gut says that the pump pumps full pressure and the regulator controles the pressure to the EFI.

The computer would control the injectors, so like the AC power in your house, you have ~2000 watts available even if you only use 20 watts.

You have full throttle fuel flow and pressure avalible even if you are only at part throttle

That's my guess too

The PCM only turns on the fuel pump via the ASD relay after is has a cam and a crank signal from the sensors. It will turn on for about 2 seconds when the key is first turned on then turn right back off. This is just to keep prime in the fuel system. Fuel pressure is regulated by the pressure regulator located on the top of the pump itself. It is a return less system. There is no loop (return line) like early fuel injection systems had.

Thanks to everyone for the info it's very helpful.

 

[toolmanmike]

They use a fuel pressure regulator. I think pretty much all late model injected vehicles use this system.

 

[robcuda]

They use a fuel pressure regulator. I think pretty much all late model injected vehicles use this system.View attachment 1715735574

Thanks for the info. Looks like the consensus is the regulator on it's own controls the pressure with no relation to ECU. Thanks guys, you are always very helpful!!