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-   -   Rewiring the fuel pump (https://www.nopistons.com/2nd-generation-specific-17/rewiring-fuel-pump-32520/)

j9fd3s 01-28-2004 05:32 PM


Originally Posted by 1971ChevelleSSV8' date='Jan 28 2004, 03:30 PM
I'm wondering how he knows it isn't receiving voltage and/or isn't pumping correctly/the proper amount of fuel.

he doesnt

Rob x-7 01-28-2004 06:16 PM


Originally Posted by j9fd3s' date='Jan 28 2004, 06:32 PM
he doesnt

we've gone to plaid

Ranzo 01-28-2004 06:19 PM

The easiest and IMO the most reliable way to rewire the pump is to go get a nice relay and splice it into the stock wiring on the rear shock tower. Using the stock 12 volt feed to turn the relay on and a large wire running from the battery to the realy to feed the pump a constant 12v.



This allows the stock system to operate normally and will shut off if in an accident. It is still fused by the stock fuse and all. The only difference is that you get a solid voltage all the time. I have been using this on my car(s) for 6-7 years now without a problem. For some reason RX-7 Wiring is not very nice. In japan everyones car was making a BWEEEEWEEEEEEWEEE sound and I wondered what the hell that sound was..... It was the GT-R fuel pump I really wanted that sound and when future mods brought on the need for a bigger pump I could not wait to hear that sound. Unfortunatley just putting the bigger pump in the car did not do it. Rewiring the pump changed all of that and stopped fuel pressure from dropping off.

Installing GT-R pumps in many different cars yielded a loud buzz and larger amounts of fuel going in the engine but on a 7 it never happens. My car currently gets about 12.5V at cruise and 13.8 at higher RPM's This is the exact Voltage that my Power FC shows on the commander as ALT. Voltage.



It has been argued to me that my way is dumb but It has worked for me for Years and was showed to me by Japanese tuning shop. I have never found anyone to dispute this way of doing it except for the Americans who do those writeups on the Web. It makes sense to do it this way instead of running large amounts of wires and moving the Resistor relay to the back of the car when you can just install a relay and be done with it. One hour maximum for this install even for the inexperienced.



Ranzo

TheCamel 01-28-2004 07:44 PM

Ranzo, one thing you might want to do is ground the pump's ground wire as well. The GT-R has a Fuel Pressure variable relay, it is in the maps of the Nissan ECU and engages a relay in the rear passenger compartment, this unit controls the ground to the pump. Removing the ground wire to the pump from the harness and grounding it to the frame will yeild you the BWEEEEEEE you desire. This puts the pump in high flow mode, Also if you leave the black plastic sleeve on the pump it will quiet it as well, Nissan wrapped the pump to keep noise down. Ask Frestyle, his little walbro is wired in this manor and it whines as well, not as loud as a GT-R pump but definately louder than stock!

Ranzo 01-28-2004 11:02 PM

Aahhh thats cool..... I ran a new seperate ground as well as the one the stock pump had just to be on the safe side. Thanks for the info though I will input that into my brain. https://www.nopistons.com/forums/pub...#>/biggrin.png

Jims5543 01-29-2004 09:41 AM

I did what ranzo did and rewired a relay running altenator voltage to my fuel pump. I get 14.3 volts at the pump at WOT.

roadkill669 01-29-2004 02:03 PM

This is a very simple thing to do. Remove the access panel to the fuel pump. You will see three terminals on the passenger side. The one towards the front is the V+(in). You want to cut the wire coming from the main harness and tape that up or something. I ended up using 8 or 10 gauge wire and modified a crimp connector so that I could lossen the nut holding the original wire and just tighten up the new one. The ground is sort of in the center of the plate. Do the same thing with the ground except hook it up to the body or the chasis instead of the battery.



Now you can use a relay or a manual switch to turn the power on to the fuel pump. I have a relay now since I have a Microtech but I used to have a 3 way switch so I could either run it using the battery power or the ecu signal.



To use the relay, just use the wire that you cut and taped up for the input signal. Just make sure that you use a high amperage relay just to be safe.





This works really good also for 2 fuel pumps like I have. It increased my fuel pressure from about 45 to 65 at wot. The microtech acts a little wierd so I may go back to my original way.

Dramon_Killer 01-29-2004 03:06 PM

This should be put into the FAQ section


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