goodspeed

is the fuel pump going to do me any good if I don't rewire it?

I need to buy a walbro fuel pump, but I don't feel confident in doing a rewire. Will a walbro do anything for me if I don't rewire it?]
thanks

Ranzo

Hmmm wonder why nobody is answering this??

if you need a fuel pump then a fuel pump will help. The rewire is only there to ensure that the pump gets 12v all the time vice 6 at idle and 12 off idle like stock.

I have seen cars that needed a rewire because the changeover wasn't happening properly but if the current pump is not doing the job then your only option is to buy a bigger one. So the answer is yes it will do you some good.

Randy....

crossbar17

how do u do the rewired? direct to battery for the power wire? or to the computer? this woukld be a tII pump install on my 88 n/a
ofcourse i would have it regulated by my safc

goodspeed

^^

my stock fuel pump gets the correct voltage, I don't think thats going to be a problem. I like the setup it has now without doing hack jobs. So basically if the cars fuel pump functions properly, the walbro fuel pump is going to do the trick , dump more fuel.

Why would anyone want more voltage at idle?? hmm. seems like this fuel pump rewire is more of a rigging than a good mod.

Im just trying to get everything ready for my turbo upgrade,

I have my super afc, avc-r,

I've ordered the fuelpump, 2 720 cc injectors, and greddy front mount from a friend

Then Im shipping my turbo off to majestic for a to4-e upgrade and wastegate port, then having it dyno tuned @12-14psi, haven't decided yet.

The turbo upgrade @12-14 psi will probably yield me 300-320 flwhp, maybe 270-280 rwhp. good enough to have a street car that runs 12's, which is what I want, but I would think the afc, avc'r, 720'c, and bigger fuel pump would be sufficient for 270 or so rwhp.

Erik

sounds like a plan

what ever happened to the new pics of your car?

Jerk_Racer

goodspeed: do you think you'll have this running in time for Apple Blossom? I'm going down the same route with my car and would like to see your setup assuming it's ready by then.

jerk_racer@hotmail.com

goodspeed

hey jerk, when is it???

Erik, I have a crappy camera, I've taken pics, but they make the car look like crap. Im sure Ill be meeting up with jerk and them guys sometime, Im sure they have a good camera.

The car looks GREAT....when the sun is out, it looks like a million dollars, everyone is giving me compliments...I've had 2 vettes, and a guy in the s2000 totally love my car. Its amazing what a full body restoration and a badass paint job can do!!!

Ranzo

Ok maybe is misspoke earlier, The rewire is to ensure the pump gets all the voltage it needs or wants in any given situation, such as stereo and all the lights on and such. In my car without a rewire I see 11.6volts at the pump. With the rewire I see 13.5-13.8v.

The changing voltage at idle makes it harder to tune, in my opinion, because the fuel pressure changes at idle and you must compensate with the maps. I just like the fuel pump to have all the voltage it needs- all the time.

But that being beside the point, the Walboro with out rewiring will do the trick.

Jerk_Racer

Woohoo! My Walbro came in the mail today.
goodspeed: ABF is the first weekend in May. Checkout the NW and readup on the lond and drawn out thread about this. If you plan on going, I hope you already have a room reserved. Hopefully by that time I might have a digital camera.

jerk_racer@hotmail.com

scathcart

This information is incorrect.
The rewire does not have the fuel pump seeing 12V all the time. The reason to keep the fuel pump resistor in the system (by moving it from the front of the car to the rear) is so that the voltage is lowered at idle. This is to add pump life so it is not at its maximum work output at idle.
The reasoning behind the fuel pump rewire has nothing to do with idle voltage, it has to do with WOT voltage. Before the rewire, the car sees lower than 12V at idle. This menas the fuel pressure drops, which can lead to detonation. The fuel pump rewire simply opens a circuit that gives the fuel pump a direct connection to the battery positive terminal.
The changing voltage at idle does not make it harder to tune! This statement is idiotic. The pump must supply higher pressure than the fuel pressure regulator sees. If the pump can do this at idle, (which it can) the idle voltage does not need to be as high. Fuel flow over the injectors has nothing to do with fuel metering, it is fuel PRESSURE. Have you even attempted to tune your car? Have you even done the fuel pump rewire? If you're getting 13.5-13.8 volts at idle, you ahve done something wrong.

GOODSPEED, yes, do the fuel pump rewire as added security with a Walboro install.
Link below:
http://www.1300cc.com/howto/how2/rewire.htm

Sean Cathcart

scathcart

You don't. Pump voltage has nothing to do with how much fuel the engine meters in, just how much fuel the injectors see. You want lower voltage at idle since the pump doesn't need to work as hard to provide a higher than fuel regulator pressure. Running a pump at full voltage at idle is stupid, it just needlessly wears out the pump and heats the fuel.
Ranzo's post was completely inaccurate.

If you have a good working system, don't do the re-wire. It is just in a lot of cars that at WOT, under electronic load, the pump sees much less that the correct voltage. With boost, this can lead to the injectors injecting more fuel than the pump can provide, and the pressure in the fuel rails drops below what the regulator is set at.
The rewire ensures the fuel pump sees correct voltage at WOT. If you have evrified this (need a friend sitting in the back of the car with a DMM on the pump while you drive at full boost. Engine must be under load!), then don't do the re-wire.
But most cars do need it.
Sean Cathcart

goodspeed

thanks scathcart

that helps a bunch!!

Ranzo

in response to scathcarts badgering and trying do disprove my posts I say this. First How do you rewire your Pump? or did you? If you open a circuit to the positice terminal of the battery you will see 12 volts all the time EVEN AT IDLE therefore changing idle voltage which will increase fuel pressure at idle thereby increasing the amount of fuel delivered into the engine. This same thing hold true for WOT and all throttle positions. If you have more or less fuel entering the engine at idle and you wanted to change that you would have to adjust the "metering" or the amount of time the injetctor was open at idle, hence making it a pain in the *** to tune. I also stated that it was "my opinion" about the problems with tuning. Changing fuel pressure is another variable that the rewire can eliminate.

Maybe you guys don't make adjustments for idle maybe you just look at WOT but I race circuit which requires a broad powerband and a car that idles nasty or too rich will foul plugs and just looks and sounds like ****.

My car is highly tuned for all of your information. My mods are : Trust FMIC, Knight Sports Turbine, KSP attain full stainless muffler, Cusco LSD-shimmed, Tein Shakocho with pillow uppers,OS Giken Twin PLate Clutch, toe contol canceler bushings, Apexi Power FC, Profec B vvc, A-RF strut tower bars Front and Rear and I run a R33 NISMO fuel pump wired via relay directly to the battery. The other misc. stuff like tires and stuff (small parts) I will not bother to list.

The information that I gave was correct. It was not incorrect. I explained that installing the Walboro without a rewire would more than likely do the job the original poster wanted to do. I also explained that sometimes FC's will not make the voltage changeover properly and this will cause hesitation and sometimes bucking. I also explained that a rewire will ensure that the pump gets maximum power at all times so that those problems are not an issue when tuning.

I have been running the same fuel pump for 4 years and it has always been rewired to see 12Vall the time. This pump still works fine and I have no pressure loss all the way to Redline even running 720CC inj. in the secondaries. Maybe you don't see 13Volts at the pump because your battery or charging sysem is weak...i dunno and don't care.

scathcart

I hope you never crash your car. Your fuel pump rewire is a hack job: a simple wire running straight from the battery to the pump tripped by a relay hooked up to the ignition. Should you crash your car, you swill spray fuel all over the place.

I did rewire my fuel pump. I retained use of the fuel pump resistor for idle so I don't put needless wear onto my pump and needless heat into my fuel.
I also rewired it so that I keep the safety switch in my AFM. This way, should I crash in racing and flip the car (and become trapped or unconscious so that I can't shut off my ignition), my pump will not continue to feed fuel to an engine fire.
But you knew this, didn't you?? Do you have any safety provisions in your so called "Race car", if it actually exists??

Your analysis of idle tuning is stupid.
Just because the fuel pump is running at higher fuel pressure does not mean the engine is seeing higher fuel pressure.
Example: The stock pump puts out say 60 psi static pressure at idle. The fuel is sent through the rails to the fuel presssure regulator, which bleeds off fuel pressure until the fuel rails see 40 psi.
If you put increase the fuel flow or fuel static pressure from the fuel pump, THE REGULATOR STILL ALLOWS THE RAILS TO SEE 40 PSI.
Running the stock regulator with a bigger pump does not require tuning at idle, unless the regulator is over taxed (by say, maybe, running full pump voltage at idle??)

You can tell us all you drive a race car but the help you are providing on here is false, and thus, I don't believe you. The work I have provided to this forum speaks for myself, whereas what you have provided is filled with rudeness and falsity.

Also, I would like to know, as I'm sure others would, how you got a Power FC for a 3rd gen engine to run on a TII.

Again, you have proved yourself wrong in your knowledge of FC's. Did you not say you had an extensive knowledge over me in this area?

Insult my car all you want, saying "Maybe your charging system is weak", but at least I know how my car works and at least I know how to assemble it correctly.

You= Poser!

Sean Cathcart

Ryde _Or_Die

This just about exactly what I want to do. And my goal is also to get in the 12s from a street car. Would love to get mid to low 12s. Make sure you let everyone know how it goes.

Ryde _Or_Die

Oh and how much does majestic charge for the turbo upgrade and wastegate porting?

Ranzo

Man you people wouldn't know the truth if it hit you in the face!!! Well Scathcart anyway, I do have the safety feature built in to my Rewire by using the same control wire that turns the stock pump on to turn on the relay that feeds the pump, you should think about it before you speak!! I never said it was connected to the ignition, that is only your assumption. This is the way I was taught by a Japanese Tuner in Okinawa- the owner of R Factory. You can ask any of the Vanquish guys on the this board or the Power FC board as they know me. The way I wired my pump is the approved method of most Japanese tuners like Pan Speed, Border, R magic, A-RF but since you don't live by those places you would not know.

Lets see how you have contradicted yourself here, a fuel pump is nothing more than an electrical motor so with an electrical motor when you increase the power going to it the work it does will increase accordingly. The stock regulator on a FC3S is just big enough to run stock fuel pump so if you had a Walboro pump, (since this is what this thread is about) im not sure about rewiring a stock pump i never tried but sure the effects would be similar, and you increased the voltage to it then the amount of fuel would overtax the regulator hence increasing fuel pressure. Fuel pressure is directly proportianal to the amount of fuel delivered into the engine. Even without a rewire the Walboro pump would "overtax" the stock regulator and you would see an increas in fuel pressure. all you need is a fuel pressure gauge to see this. I never said anything was set in stone, I said that the way I do it is the way i like it and those are MY reasons.

And lastly for all of you non believers out there, I do have a Power FC I can provide pictures and reciepts for it. I had it installed at Border which is located in Mizuho city Tokyo Japan about 10min from my Apt. Just because you can't buy it at Jimmys tuning shop in Central america don't mean it don't exist!!! Ap engineering which is the main company of Apexi makes Power FC's for almost any car in the world, if you ask and got the cash you can get it. I run no air flow meter and I have a Apex boost sensor, Apex air temp Sensor and others too. You know I was going to mention this to the Board because I can probably get them imported to the states because my friend works there doing Import/export deals. However with the temperment of this board and since you all know everything I don't think I will do that now.

Scathcart I am sure that you have helped many people on this board and other places, everyone here has some knowledge about something but just because you don't like me or you think I am a poser does not give you any right to **** with me. I only speak what I know and if I am wrong I will admit I am wrong but I would say the biggest problem is your Tone. You attacked me on this board not the other way around so I am asking you to back off as I will no longer respond to any **** that you talk to me.

HAILERS

http://www.majesticturbo.com/

Jerk_Racer

Damn! That's a burn! Ranzo, you da man! Scathcart, walk away and keep what's left of your dignity.