Tuning Return Style Fuel for 4.6l 3V swap

Can anyone guide me in the right direction for the requirements for adjusting my fuel settings when running a return style fuel system?

2006 4.6l 3v out of mustang gt.
I have an intank aftermarket pump run to a regulator which returns to the tank and feeds the stock fuel rails.
Only mods are Airaid 100mm CAI, Ford Performance M-9593-LU24A injectors.
Fuel system is controlled by a relay that is energized when the key is turned to run/start.
No FPDM, no EVAP, only front O2 sensors are being used.

In my tune so far I have disabled adaptive fuel voltage, I have also modified my MAF for the CAI, as well as adjusted my injector control settings for my specific injectors, Pats is disabled, and rear O2 sensors are set to none.

Am I missing anything that I need to adjust when using a return style stand alone system? I seem to get a lot of fuel when first trying to start it and I think it may be flooding my engine causing a no start.

Thanks D

You need to go into the fuel system window, fuel pressure tab and set all of those to whatever pressure your running.

Go to
1- fuel system >Fuel Pump, Desired voltage set to maximum 15V.
2- Disable adaptive voltage. Enable fixed duty cycle.
3- go to Fuel pressure and set the pressure to what you set the regulator.
4- Go to Fuel diagnose and disable test and mil and disable EVAP.
5- Got to engine diagnose>Exhaust Disable Cats test and mil
6- Disable all codes related to fuel pump module, fuel rail pressure, EVAP, O2 sensors sensor 2 Only and DTC 420, 430
7- Go to engine> Fuel> oxygen sensor set rear config to none, and set heaters to 0 for S2.

These steps will work for either if the fuel pump is connected to the FPDM or not.
Hopefully I did not forget something.

when swapping from returnless to return you should have the fuel rail pressure sensor still present on the rail and working so you dont need to mess with any pressure settings.

leave all the fuel pump and fuel system switches as stock except for the pump voltage which youve disabled and just disable any trouble codes that pop up for the fpdm offline and such.

no tune changes are required whem going from returnless to return except for disabling the codes.

the ecu needs to be set for returnless still so it uses the fuel rail pressure sensor to correct fueling for any fuel pressure errors.

Quote:

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Originally Posted by decipha

when swapping from returnless to return you should have the fuel rail pressure sensor still present on the rail and working so you dont need to mess with any pressure settings.

leave all the fuel pump and fuel system switches as stock except for the pump voltage which youve disabled and just disable any trouble codes that pop up for the fpdm offline and such.

no tune changes are required whem going from returnless to return except for disabling the codes.

the ecu needs to be set for returnless still so it uses the fuel rail pressure sensor to correct fueling for any fuel pressure errors.

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Thank you Decipha for your input. So what if the fuel rail pressure sensor is not fitted? Would it result in bad fueling?

Quote:

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Originally Posted by B E N

You need to go into the fuel system window, fuel pressure tab and set all of those to whatever pressure your running.

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Done.

Quote:

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Originally Posted by yaqoubalmounes

Go to
1- fuel system >Fuel Pump, Desired voltage set to maximum 15V.
2- Disable adaptive voltage. Enable fixed duty cycle.
3- go to Fuel pressure and set the pressure to what you set the regulator.
4- Go to Fuel diagnose and disable test and mil and disable EVAP.
5- Got to engine diagnose>Exhaust Disable Cats test and mil
6- Disable all codes related to fuel pump module, fuel rail pressure, EVAP, O2 sensors sensor 2 Only and DTC 420, 430
7- Go to engine> Fuel> oxygen sensor set rear config to none, and set heaters to 0 for S2.

These steps will work for either if the fuel pump is connected to the FPDM or not.
Hopefully I did not forget something.

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I will have a look at this.

Quote:

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Originally Posted by decipha

when swapping from returnless to return you should have the fuel rail pressure sensor still present on the rail and working so you dont need to mess with any pressure settings.

leave all the fuel pump and fuel system switches as stock except for the pump voltage which youve disabled and just disable any trouble codes that pop up for the fpdm offline and such.

no tune changes are required whem going from returnless to return except for disabling the codes.

the ecu needs to be set for returnless still so it uses the fuel rail pressure sensor to correct fueling for any fuel pressure errors.

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If I go this route does it mean don't change the settings as per post #3?


Thanks D

its never wise to remove the stock fuel pressure sensor.

If its removed when doing a return swap it wont cause any issues but you wont be able to log fuel preasure and the ecu cant compensate if fuel pressure drops off up top for a weak pump or the like.

There is a lot more safety with the fuel rail pressure sensor present and it could help diagnose possible issues easier as well some day later down the line.

Not to mention the #1 cause of engine failures are from running lean which is usually due to weak fuel pumps.

When keeping the fuel rail pressure sensor and swapping to return you only have to disable the P123x codes for the fpdm offline and disable the fuel pump adaptives.

I would also highly recommend keeping the fpdm and running the wires that originally went to the stock pump to a relay instead that turns your new return pumps on and off. Additional youd have to set the fuel pump min duty cycle to 0.50 as well.