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Discussion Starter #1 (Edited)
Time has come to start my fueling setup.

I have ripped out my OEM fuel lines and will be shaping up some goodridge aluminum hardlines for the feed and return.
All the grease monkey work of it all is easy enough, but the electrics l do not understand so much.

Came across this thread; RDR 3000GT/Stealth Fuel Pump Rewiring

RDR 3000GT/Stealth Fuel Pump Rewiring Details

The theory is sound and supposedly applicable to all cars once you undertstand YOUR CARS wiring.

I understand that alot of DIYer's like to 'hot wire' there fuel pumps in order to maintain the battery voltage to fuel pump of 12-13.5v (using the oem live from ecu, fuse and relay to battery, thicker wire to fuel pump, thus sustained voltage) hope l got that right:nervous:

But, am l understanding the link up top, in, it showing how you can keep the OEM variable voltage to the pump/s so that on idle it runs a lower voltage and high, when the pedal is to the metal.

Is my prefered way of setting up the fueling via variable voltage to pumps/s suitable for high horse power motors or is the easy way, 'hotwire' method more suitable.

The reason l ask is, a friend noticed when fueling was apparently setup in the OEM variable voltage to the pumps on a GTIR with the PFC ecu, the time it took for the pump to switch from the lower voltage to high, det/knock occured... ...can anyone confirm or rubbish this statement.

All this aside, l'ved searched and cannot find a suitable thread that could explain to me with pics of how to do it, cause anything to do with electrics, i just dont get it without pics!! Yes l know, thick as shit!


Can anyone help pleeeeeeaaaaase.!!!!!!!

Many thanks.
 

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I would just rewire the pumps to run at battery voltage as the other reason for bypassing the fuel voltage regulator is that they do go wrong.

Also the standard wiring is not designed to run 2 pumps. We just run new powers and earths to the pumps and use the original wiring to switch them via a relay.

Richard
 

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As above, as thats whats been done to mine and I'm running 2 Bosch external pumps with a swirlpot. Ready made by RIPs.
 

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Discussion Starter #4
thanks for the replies guys and a valuable point on the part failing.


cheers,

naz.
 

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I am running a stock type, but higher than stock flow, in tank lift pump to a swirl pot, with the pot feeding two Bosch 044 Motorsport pumps feeding to the rail. I am running a Motec M800 ECU. I asked on Motec's support forum about running both pumps together and they strongly adised I run two realys, one for each 044 pump, and use the Motec to switch the second pump in as and when needed based on engine load. The reason being that two 044's at idle could overwhelm the FPR or return line and fittings, giving an unnaturally high idle fuel pressure. Here are links to my posts:

http://www.motec.com.au/forum/viewtopic.php?f=39&t=827


You may find this on fuel heating useful, too:

http://www.motec.com.au/forum/viewtopic.php?f=39&t=864
 

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I havent read your threads in depth, but... To "hard wire" your pumps via a relay, Which is what i did. You run the earth directly to battery, or a very good body earth (Use wire that is capable of delivering 15amps+ per pump.)
Get a 4 pin relay ( ive got a 30 amp relay, but Im only running one HKS pump.Higher amp relays are availiable) The pins on a 4pin relay, are numbered 85,86,30 and 87. Pins 85 and 86, are for the switching windings and 30,87 is where your current runs through.
Take your permanant live wire directly from the battery, and connect it to pin 30.From pin 87,wire to the live side of the pump.
Pin 85 should go to earth (5, or 8 amp wire).
Connect the original pump live to pin 86 on the relay. Done. Mount the relay so it looks good.

A standard pump uses approx 5amps on tick over, so allow 15 for a proper one. put a fuse in the main live. 20amps per pump id say, and use the same amp rated wire you use for your earth. you could run one, or two relays it depends what you want to do.
This method allows the ecu to switch the pumps as intended.:thumbsup:
 

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As a matter of curiosity, how much current will the OE pump controller handle? Is it relay operated and just switches contacts over, or solid state? What device drops the voltage? Does it just output either full battery voltage and one lower voltage, or is it linear? Thanks.
 

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I havent read your threads in depth, but... To "hard wire" your pumps via a relay, Which is what i did. You run the earth directly to battery, or a very good body earth (Use wire that is capable of delivering 15amps+ per pump.)
Get a 4 pin relay ( ive got a 30 amp relay, but Im only running one HKS pump.Higher amp relays are availiable) The pins on a 4pin relay, are numbered 85,86,30 and 87. Pins 85 and 86, are for the switching windings and 30,87 is where your current runs through.
Take your permanant live wire directly from the battery, and connect it to pin 30.From pin 87,wire to the live side of the pump.
Pin 85 should go to earth (5, or 8 amp wire).
Connect the original pump live to pin 86 on the relay. Done. Mount the relay so it looks good.

A standard pump uses approx 5amps on tick over, so allow 15 for a proper one. put a fuse in the main live. 20amps per pump id say, and use the same amp rated wire you use for your earth. you could run one, or two relays it depends what you want to do.
This method allows the ecu to switch the pumps as intended.:thumbsup:
I also have 2 044's under my swirlpot, both running via 1 relay, if I isolated 1 pump and gave it its own relay and did the wiring as you have explained, will that make the 2nd pump switchable to on and off as to when its needed, or is there more to it than that??
 

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hard wiring to the battery is simpler and eliminates one potential point of failure (the variable voltage thing).

But if one wanted variable voltage, I'd go with an Aeromotive Fuel Pump Speed Controller, which is mappable with fuel pump voltage versus rpm. This fuel pump computer is easy to map to - if you can set an EQ on a stereo, you can map this fuel pump computer.
 

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Different car (300zx) but I have twin Walboro in tank pumps, and added a second Fuel Pump controller module to run the second pump with the variable voltage. Quite simple to wire up and seemed a more elegant approach.
 

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Discussion Starter #12
chris wilson
I am running a stock type, but higher than stock flow, in tank lift pump to a swirl pot, with the pot feeding two Bosch 044 Motorsport pumps feeding to the rail. I am running a Motec M800 ECU. I asked on Motec's support forum about running both pumps together and they strongly adised I run two realys, one for each 044 pump, and use the Motec to switch the second pump in as and when needed based on engine load. The reason being that two 044's at idle could overwhelm the FPR or return line and fittings, giving an unnaturally high idle fuel pressure. Here are links to my posts:

www.motec.com • View topic - Fuel pipe size requirements for 700 BHP turbo engine


You may find this on fuel heating useful, too:

http://www.motec.com.au/forum/viewtopic.php?f=39&t=864
I hear you on the fuel heating chris, but does this still matter if l was running both my pumps in tank, also if l was to use a fuel cooler (radiator) would it help. (think the nissan patrol has one as OEM fitment)





Aeromotive Fuel Pump Speed Controller - Tech
The original FPSC P/N 16302 measures 5.20 inches wide by 3.5 inches long by 1 inch high and weighs 1.08 pounds. The new FPSC P/N 16306 is half the size and weight-3.25 inches wide by 3 inches long by 1.1 inches high. The original incorporated a solid state circuit board permanently potted into a billet enclosure; the new model features solid state circuitry as well, but takes advantage of modern, miniaturized components to significantly reduce overall circuit board size, followed with a special clear coating for moisture resistance that allows the elimination of the potting compound. In addition, the new model features an integral heat sink in the billet case, plus advanced control features and enhanced ease of operation.


At first glance, the Aeromotive Fuel Pump Speed Controller (FPSC) looks like a simple black box filled with LEDs, screws, and resistors, but you'll be surprised to know that it's so much more. This state-of-the-art electric fuel pump control module was recently released by Aeromotive as the second-generation controller, replacing the previous model that serviced the race community for a stellar eight years. The new FPSC was designed to provide the end user with ease of programming, plus its use of pulse modulation reduces pump speed without harming the motor and ultimately its function in order to allow large, high-flow fuel pumps to be street driven by minimizing fuel heating that can rob a vehicle of horsepower and performance. "The motivation for the FPSC redesign was primarily to enhance operation and the user interface, while reducing size and weight," Brett Clow says, Aeromotive engineer. "Additional desired benefits included reduced build time and costs, along with enhanced serviceability."

Why Use The Aeromotive FPSC
"Ultimately the purpose of installing the Aeromotive billet FPSC is to control the fuel recycle rate and minimize heat transfer from the engine compartment into the fuel and thereby back to the tank," Clow says. Interestingly, reduced fuel heating in the tank is the purpose of today's "returnless" fuel systems, but with significant reduction in fuel system performance. As a side bar, "returnless" fuel systems are totally EPA driven with respect to evaporative emission control (EEC) standards. Not to say that the Aeromotive FPSC is an EEC device, or that it would eliminate fuel heating completely, but it does in fact reduce residual fuel heating in the tank in order to extend the driveability of a high-performance fuel system and as a bonus helps reduce the tendency for hot-fuel vapors to pollute the environment for the more environmentally conscious. Added benefits when using the Aeromotive FPSC include extended pump service life and quieter operation at lower rpm when cruising the streets.
This product sounds very interesting 'Kismacapitan', what does this product retail for?, do you think l could wire both my intank tomei pumps to it?... and can it be mapped via a pfc d-jetro?

Jaffa
Different car (300zx) but I have twin Walboro in tank pumps, and added a second Fuel Pump controller module to run the second pump with the variable voltage. Quite simple to wire up and seemed a more elegant approach.
Was this device a variable/controller (2 in 1) and what make was it it. Was it easy to wire in?
 

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Jaffa


Was this device a variable/controller (2 in 1) and what make was it it. Was it easy to wire in?
the 300zx comes with a Fuel Pump controller as standard to control the voltage to the stock pump, so I picked up a 2nd hand unit from a breaker, wired the inputs in parallel and the outputs to the second pump.
Basically it works by the pumps taking an ign live and the earth goes through the controller so it can vary the resistance thus changing the pump speed.
 

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Discussion Starter #14
Did you modify the wiring to sort out the voltage problem aswell, the low voltage from ecu to pump, so thicker wire etc etc thus sustaining the 12-13.5v.
 

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Did you modify the wiring to sort out the voltage problem aswell, the low voltage from ecu to pump, so thicker wire etc etc thus sustaining the 12-13.5v.
not needed on the 300zx, the wire from the ecu is just a load signal, the main voltage is direct from the main harness through a dedicated fuel pump relay.

Hope that makes sense.
 

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No mate, it would mean they both run the same speed as each other. If you wanted to do that, it would mean getting a controller.
I would just run them at full speed (unless the noise drives you mad!)

I also have 2 044's under my swirlpot, both running via 1 relay, if I isolated 1 pump and gave it its own relay and did the wiring as you have explained, will that make the 2nd pump switchable to on and off as to when its needed, or is there more to it than that??
 

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They're both running at full speed, which is a waste most of the time as its normal driving. Obviously when giving it the beans you need both on song. The noise is irritating, wasn't at first, but it is now, are there any silent running pumps available, or is relocation the best thing, I'm assuming the swirlpot would need to be close to the pumps ??
 

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Discussion Starter #19 (Edited)
Okay, coming to some kind of resolution as to what my fueling system is going to be.

Decided on 'hardwiring' the two intank pumps, 2/3 of the piping will be goodridge alu hardlines.

So your opinions/advice please;

Two braided -8 feeds from the pump sender with two inline checkvalves, 'Y' peiceing into the -8/12mm alu hardline.

Hardline finishing just before the fuel rail, into a billet fuel filter, 'Y' peiceing into two -8 braided lines feeding -8 entries on either side of the fuel rail.

Return is via a single -6 braided hose, through a tomei billet 'L' type FPR and inline pressure gauge, connected on to -6/9.5mm alu hardline up to, before the sender and then -6 braided line into sender.

Now as chris has said, am l going to have any issues with the pressure/heat on idle/full throttle of the fuel on its return that l need to be worried about.

Also l noticed some kind of OEM fuel dampner up by the fuel tank and up front before the OEM fuel filter.... does a fuel dampner of some kind need to be fitted to the fuel system.

cheers.
 
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