Still trying to figure out the relay wiring for the higher capacity fuel pumps

[Fastguy]

Still scratching my head at wiring for these pumps. I have a walbro 450 in tank and a Bosch 044 inline for outside. I understand both pumps need to be either on or off; 0 or 12V. The stock system, as we all know, is controlled by a fuel module with 0, 10, or 12V (which I'm guessing is located below the steering wheel in the relay panels).

I was was told I need to retain the stock control module as it communicates with the ecu. I purchased a relay kit : http://www.ebay.com/itm/Painless-Wir...JTn3mu&vxp=mtr

its a standard relay. Needs battery power and a switched lead to close the contacts to the new pumps. I'm assuming the 30 amp contacts are plenty to hold power for the two pumps run in parallel off the same terminal on the new relay.

I have two questions at this point;

1. Does anyone know exactly where the fuel pump control module (j538) is located?

2. I was thinking I would tap the section of wire between j17 and j538 as my switched lead to close the relay. Then the only issue is, I would just isolate the stock pump conductors, but I assume the module will send an error state to the ecu

http://s17.postimg.org/hn473llm7/image.png

[nubcake]

1) The whole "communicates with ECU" deal can be bypassed by custom ECU code.
2) Both pumps can run on variable voltage AFAIK. I'm not 100% on walbro, though.

I recommend retaining the module for two main reasons:
- Preventing excessive fuel heat-up.
- Stabilizing voltage to pumps. "Control module" does that as well. Especially if you're running MT. Voltage pulsations with heavy electical load and in low RPM can lead to some very funny (not) situations.

Can't give you precise location of the control module, but AFAIK it's somewhere behind the right rear seat.

[Fastguy]

1) The whole "communicates with ECU" deal can be bypassed by custom ECU code.
2) Both pumps can run on variable voltage AFAIK. I'm not 100% on walbro, though.

I recommend retaining the module for two main reasons:
- Preventing excessive fuel heat-up.
- Stabilizing voltage to pumps. "Control module" does that as well. Especially if you're running MT. Voltage pulsations with heavy electical load and in low RPM can lead to some very funny (not) situations.

Can't give you precise location of the control module, but AFAIK it's somewhere behind the right rear seat.

So you are saying to let the 044 run with variable voltage, no aftermarket relay for it. If the walbro will work with variable voltage, great. Let it use factory wiring and run it variably. If it won't, then I'll only need to relay that pump to run 0 or 12?

[lswing]

Just to mention, as far as the Bosch 044 goes (the out of tank inline pump) it seems to bolt in and work with zero issues, and generally better feel due to the extra fuel pressure. I should have mine installed soon, will report.

[nubcake]

So you are saying to let the 044 run with variable voltage, no aftermarket relay for it. If the walbro will work with variable voltage, great. Let it use factory wiring and run it variably. If it won't, then I'll only need to relay that pump to run 0 or 12?

As mentioned, 044 is bolt-on. Get someone else to confirm on walbro, but as far as I'm concerned, it should be bolt-on as well.
The whole "aftermarket relay" deal sounds excessive. Try "the factory way" first.

[Fastguy]

I am doing this just for more fuel. I'm topped out now at 19 psi of boost. I was told, for my 550cc injectors, the walbro 450 with the 044 inline should get me more fuel. I think it should be plenty, as the 2.7, with an 044 alone will support over 600 whp.

[nubcake]

I am doing this just for more fuel. I'm topped out now at 19 psi of boost. I was told, for my 550cc injectors, the walbro 450 with the 044 inline should get me more fuel. I think it should be plenty, as the 2.7, with an 044 alone will support over 600 whp.

Wasn't arguing against upgrading fuel pumps, just made a notice about wiring them.

[Fastguy]

Wasn't arguing against upgrading fuel pumps, just made a notice about wiring them.

Sorry if it came off that way. I was actually fishing for someone to say,"oh, those two pumps should give you plenty of fuel for what you are trying to accomplish"

actually, your response makes me hopeful. Much much simpler to just fit the pumps and wire right back in to existing wiring. I can't wait to get them installed now. After this last thing, I think I'm complete.

Got my coilovers installed, going to adjust for what I feel is optimal height, new nozzles for the water/meth on the way, installing the two tone alcantara door cards and alcantara seats, prop shaft sent off for new cv and center carrier bearing, fuel tank rollover valve leak repaired by dealer under recall, exhaust straight pipe fabricated which will leave resonators and delete rear mufflers, and think I'll order Hodgkis sway bars tonight. That, besides final tuning, pretty much wraps it up! I can't wait. 550 whp here I come