Are there any alternatives to rewiring the fuel pump in order to make sure it's getting full voltage? I was planning on doing it next week, i have a friend coming over who has done this to his DSM. I'm just afraid that it won't come out right and my engine will go teh pop.

why dont you chack the voltage first, if its good then you're done

rewire the positive cable to a 12V and the negative cable to a ground.......

How do i check voltage?



And Fre, i read a writeup on how to rewire the pump and i remember it being a lot more complicated than just two things.

bump

voltmeter ....









theres one on rx7turbo.com ... or 1300cc.com ...

i was reading that one (1300cc.com) the other day, and it didnt help me much :( Maybe i should read it again. But it really didnt talk about what to do witht he resistor relay (thats connected to the fuel pump relay). I also need to do the fuel pump rewire.

I had a link my point was that they make it sound really long and tedious and hard.

well it is, take it from the lazy man, check the voltage first, its your only way out of working hard

Well it really isn't that hard... https://www.nopistons.com/forums/pub...IR#>/dunno.gif



I can't understand why it would be a tedious task..

get a standalone...it took sean and i about 4 minutes to do the job....running the wire was the only long thing

get a multimeter from walmart, run two peices of wiring from your fuel pump harness in the rear hatch area under the carpet, and hook it up to your multimeter.



then, drive your car around, with your multimeter in your lap, reading the voltage.



i got like 7.5V at idle, 8V while cruising, and 10.5 - 11 V at WOT and full boost. should be like 9V at idle and 12.5V at WOT and full boost, but those 2 volts aren't worth it for me to rewire the whole system.



you can also get a bigger fuel pump, then you wont have to worry about too little fuel flow. https://www.nopistons.com/forums/pub...IR#>/bigok.gif

it is. it took me a whole day (6-8 hours?) of taking my time and checking everything over a few times.



the DSM rewire is easy and takes about 30 mins...





you could do it the DSM way and just run constant 12v to the pump all the time. then you just run new wire into the back. and use a relay on the stock wire and new wire. but it'll probably end up causing you to run pretty rich at idle and cruise. especialy with a bigger pump

If you are asking that, then you shouldn't be dicking around trying to rewire it.

you might also wanna check the battery voltage under the same conditions, just a thought

It's not too hard, it took me a few hours to do. The drawing on www.1300cc.com really helped. Just take your time and double check all your wiring as you go and it should be fine. I don't recommend wiring it to see full voltage all the time. It'll make your car run super rich at idle and possibly smoke. And check the voltage before and after.

What's wrong with the fuel pump anyway that requires you to mess with the wiring?

apparently the fuel pump wiring gets old/bad so the pump doesnt recieve full voltage.

I'm wondering how he knows it isn't receiving voltage and/or isn't pumping correctly/the proper amount of fuel.

he doesnt

we've gone to plaid

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

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!

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

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.

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.

This should be put into the FAQ section