Return style wiring HOW TO allowing OE type fuel pump actuation

[Wicked46]

so you just left the wire on the plug side hanging correct?

Do you have the Lethal budget kit? Just wire the relays up like I have them in my diagram above. Add a switch in there to if you'd like...

 

[sn94cobra]

yes, thats the way i did mine from malcolms instructions.. you can do the switch like he shows to test the pumps and set pressures or i just grounded the relays with my test light to run the pumps. it was to late to get a switch and i wanted to check for leaks.. Thanks again to malcolm for the post

Do you guys set press with engine off?

I have always set press with engine running vacuum removed.

 

[Leo0916]

I was told to set it at 40psi with engine off and with engine running it should be around 35 psi.. Ill know when i get the tune, waiting on that to still come.

 

[sn94cobra]

I was told to set it at 40psi with engine off and with engine running it should be around 35 psi.. Ill know when i get the tune, waiting on that to still come.

Never heard of that.

 

[jackers]

Has anyone tried to wire in a dual channel boost a pump with this setup?

 

[BO TY KLR]

So what needs to be changed in the tune? Not sure if i missed it?? I wired my walbo 400's pump up this way and right now I get surging fuel pressure(20-50#). Goes away as soon as i toggle the ground switch.

 

[MalcolmV8]

So what needs to be changed in the tune? Not sure if i missed it?? I wired my walbo 400's pump up this way and right now I get surging fuel pressure(20-50#). Goes away as soon as i toggle the ground switch.

Is your relay clicking on and off? Your relay is been driven by the FPDM right? So for the fuel pumps to be surging I'm assuming the relay is going on and off.
Have your turner change your tune from returnless to return style. Assuming it's all wired correctly that'll take care of it.

 

[BO TY KLR]

I have been running them with the green/yellow trigger wire just fine. Tuner is aware of return style system so not to throw codes. Tried wiring this way and started surging, can't really hear the relays once car fires. Everything works except for pressure surge. Almost like the driver module is trying to control voltage with ground. If I switch the toggle i have wired into ground, they run fine. Does the tuner have to change driver module to give full voltage somehow?

 

[MalcolmV8]

Yes it's much more than just turning off codes. You actually change quite a few settings in the tune but I'm sure your tuner knows this or he wouldn't be tuning cars for a living.

So if you turn your key on do the fuel pumps prime like stock and then turn off? If you flip the switch do they come on constantly and stay on as long as the key is on?

Also try and take a digital volt meter and see if you have a steady 12 volts at the relay when the car is running with the toggle switch flipped. Then turn off the toggle switch and see if you still get a steady 12 volts on the relay or not.

 

[Wicked46]

As Malcolm said, the FPDM needs to be changed in the tune to run "FULL TIME" 100%. Your tuner will also see 100% duty cycle from your pumps...

 

[Termilvr]

will this setup stop the pumps if you get into an accident?

 

[MalcolmV8]

will this setup stop the pumps if you get into an accident?

Yes pumps will operate as stock. Pop your inertia switch to test.

 

[BO TY KLR]

Yes it's much more than just turning off codes. You actually change quite a few settings in the tune but I'm sure your tuner knows this or he wouldn't be tuning cars for a living.

So if you turn your key on do the fuel pumps prime like stock and then turn off? If you flip the switch do they come on constantly and stay on as long as the key is on?

Also try and take a digital volt meter and see if you have a steady 12 volts at the relay when the car is running with the toggle switch flipped. Then turn off the toggle switch and see if you still get a steady 12 volts on the relay or not.

Thanks. Ok Now I know it needs to be tuned to 100%. Thats what I was wondering. Yes they come on and prime then stop. Everything works as they are are suppose too just need to get tuner to work it out.

 

[03mustang92]

Anyone running a check valve with this return setup? Just curious as I have got my Power wire from the fuse block, the signal pin as bn/pk from fpdm plug, halfed the bn/pk for the other side of the relay. then grounded the relay to the chassis and the pumps still prime but the thing is i dont have any fuel pressure until i cycle it around 5 times but it wont hold.

looks exactly like this

 

[03mustang92]

BTW i just read that RD/Bk was a positive and BN/PK is negative and then i read another thread it was just the opposite

 

[MalcolmV8]

Anyone running a check valve with this return setup? Just curious as I have got my Power wire from the fuse block, the signal pin as bn/pk from fpdm plug, halfed the bn/pk for the other side of the relay. then grounded the relay to the chassis and the pumps still prime but the thing is i dont have any fuel pressure until i cycle it around 5 times but it wont hold.

No check valve required. The fuel pressure regulator works as one and holds pressure. You should not have to cycle your key 5 times. Just a single turn of the key will have enough pressure. Just like OEM. How do your fuel lines route?

BTW i just read that RD/Bk was a positive and BN/PK is negative and then i read another thread it was just the opposite

BN/PK is pin 10 which is positive.

 

[03mustang92]

No check valve required. The fuel pressure regulator works as one and holds pressure. You should not have to cycle your key 5 times. Just a single turn of the key will have enough pressure. Just like OEM. How do your fuel lines route?



BN/PK is pin 10 which is positive.

Ive done alot more reading and you are correct, BN/PK is positive, Fuel line is routed next to the stock fuel line which is now my return

 

[03mustang92]

Mustang Forums and Ford Performance Forums at ModularFords

got positive an negative mixed up due to this^^^

 

[MalcolmV8]

Ive done alot more reading and you are correct, BN/PK is positive, Fuel line is routed next to the stock fuel line which is now my return

I was meaning more like the actual diagram of your fuel routing. I was wanting to see if there's a reason yours is not keeping pressure. For example mine looks mostly like this

 

[03mustang92]

Sloppy but it works