255 rewire

[hondaslayer1]

would it be a waste of time and gas to rewire my walbro 255 fuel pump. also if i do rewire it how much louder will the pump get when i drive.

 

[907dsm]

Def not a waste of time... but if your concern is about your pump being louder then I don't know to tell you.

 

[nightracer91]

I highly recommend the rewire only because getting the most out of my fuel system is a must. With the stock wiring, any excessive load is slowing your pump down and when you are under full boost, needing every precise drop of fuel, having a lean spot is not the safest thing to play with. It's pretty cheap and not too intense to do, I see you have a good list of supporting mods, might as well clean up one more thing. IMO.

 

[hondaslayer1]

i have 02 dump and vented bov lound is not a problem. just want to know if it is worth doing and what do u gain from a rewire on a 255.

 

[nightracer91]

You can a much more consistent pressure keeping your tune much more accurate.

 

[hondaslayer1]

ok i have my battery relocated to my trunk thats also why i ask. with it in the trunk make the rewire easy less wire.wanted to do it a while ago but did not know what it would do to my 255 if it would gain or hurt me in the long run.

 

[jeffo]

I don't even see an injector upgrade in your mods. A 255 rewire is going to do absolutely nothing for you. In fact, if you don't have a good AFPR its going to make the FPR overrun even worse, and make you very rich at idle and light cruising. A non-rewired 255 pump can still supply enough fuel for 650cc injectors at 100% Duty Cycle. Have you done the modification to the siphon tube in the fueltank? That's pretty much a must with a 255 pump in an AWD 2G, especially with a rewire:
http://www.dsmtuners.com/forums/bolt-tech/298712-high-fp-after-installing-new-wally-255-hp.html

 

[hondaslayer1]

whats the fuel pump tube mod for a 255. i am planing on upgrading to hx35 750cc injectors external wastegate setup real soon here.

 

[redrockergsx]

how do you rewire you fuel pump i have a 255 walbro and have heard of hot wiring is that the same and what is it when you do that.

 

[hondaslayer1]

you use a relay and oversized wires and wire in to the stock harness for the fuel pump to flow more fuel to the rail.

 

[motozachl]

vfaq is your friend Fuel pump rewire

 

[GSXeclipsePSI]

Not too jack your thread. But I was re-wiring my fuel pump, it worked fine before. I messed up on the relay There is a 87 87A or w.e. and with my vision I messed it up and maybe grounded it out.

If so where is the fuel pump relay so I can check it. My next step is to check the ECU pin out for FUEL PUMP RELAY see if that works. Cause the wire at the pump has NO power.

If not can I just run my fuel pump trigger wire to ACC or a switch?

 

[hondaslayer1]

should be in the fuze box under the hood or under the dash.

 

[donniekak]

Not too jack your thread. But I was re-wiring my fuel pump, it worked fine before. I messed up on the relay There is a 87 87A or w.e. and with my vision I messed it up and maybe grounded it out.

If so where is the fuel pump relay so I can check it. My next step is to check the ECU pin out for FUEL PUMP RELAY see if that works. Cause the wire at the pump has NO power.

If not can I just run my fuel pump trigger wire to ACC or a switch?

I run heavy wire off of a 50 amp fuse at the battery to a 90 amp switch, to my fuel pump(s). Works great, when i do fuel system work i can shut off the pump and leave the car run to bleed pressure. I can also pressurize the fuel system with the car off for troubleshooting. And, it's hidden so thiefs will be

 

[hondaslayer1]

nice but is that a little over kill for a safety feature.

 

[GSXeclipsePSI]

So its ok to not have the ecu side connect and just use a normal 12v signal to trip the relay. Where should I look 1st tho to see what I might have blown or fried. Grounding it out wouldn't have made its way to the ECU right, everything works fine EvoScan opened and said it activated the actuator but nothing. Maybe the relay is shot, is it behind the radio like the starter? I just would like to have it factory again before I go to a switch. Even tho the car is far from stock.

 

[Calan]

I run heavy wire off of a 50 amp fuse at the battery to a 90 amp switch, to my fuel pump(s). Works great, when i do fuel system work i can shut off the pump and leave the car run to bleed pressure. I can also pressurize the fuel system with the car off for troubleshooting. And, it's hidden so thiefs will be

I don't know how much current the Supra pump draws, but you might want to check that. A Walbro 255 HP only draws about 10 amps at 70 psi (more than 25 psi of boost), in which case a 50 amp fuse would be WAY too high for safe operation.

Walbro current draw

FWIW I run a 20 amp fuse on my 255HP rewire with no problems.

 

[hondaslayer1]

u are takeing my thread and it is going in a way different direction. please people lets stay on course. whats the advantage to the 255 rewire. whats the draw backs to doing this mod. also what mods do u need to support the rewire.

 

[GSXeclipsePSI]

I just found out its the MPI relay. I'm going to go check it.

My car is empty, I'm doing my wiring project.

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The RRE results provide that it provides more constant voltage to the pump. I wouldn't assume any car mod level wise would not benefit from this mod. A constant fuel pressure of 43psi is good and maintaining 1:1 ratio at the lph the pump is rated at would put it in the range in was designed to operate.

I have no clue if cars designers estimate what the voltage loss is over the wires. But a 12v pump not running on 12v is not running its rated lph.

 

[hondaslayer1]

where did u tap ## signal wire for that huge tach gauge want one installed in to my dsm.

 

[GSXeclipsePSI]

at the ecu, when you take the air vent out its really easy to run a wire down the dash to the radio/ecu area. I also had already tapped the ecu prior for the TT and AFC I had wired in. But if I'm not mistaken you can get the signal from the coil pack also. As one of the 3 wires is it on the plug under the hood.

 

[Calan]

u are takeing my thread and it is going in a way different direction. please people lets stay on course. ...

where did u tap ## signal wire for that huge tach gauge want one installed in to my dsm.

So when I mention the current rating for the fuel pump fuse, that is "taking your thread and going in a way different direction", but you asking about how to wire in a completely unneccessary "huge tach gauge" isn't?

Whatever. There are 329473294793284 threads on this site about the fuel pump rewire. This thread should have been locked as soon as it was posted.

 

[donniekak]

I don't know how much current the Supra pump draws, but you might want to check that. A Walbro 255 HP only draws about 10 amps at 70 psi (more than 25 psi of boost), in which case a 50 amp fuse would be WAY too high for safe operation.

Walbro current draw

FWIW I run a 20 amp fuse on my 255HP rewire with no problems.

I've been known to run 2 pumps, and lots of boost at up to 60 psi base pressure. A 20 or 30 is fine for the wally, and a ground out will blow any fuse.

 

[GSXeclipsePSI]

Lets not get too hostile

 

[Calan]

I've been known to run 2 pumps, and lots of boost at up to 60 psi base pressure. A 20 or 30 is fine for the wally, and a ground out will blow any fuse.

I figured you had your reasons based on the posts I've read from you in the past, but thought it wouldn't hurt to mention it.