Fuel pump re-wire/hotwire - who has done it? - 3000GT/Stealth International Message Center

GTOJOE · 07-18-2010, 08:19 PM

Has anyone done this? Has anyone else had the same issues Jeff had with unstable fuel pressure? I am using the stock pump while he was using the Supra pump. However at some stage I plan on fitting a Walbro pump instead.

Stealth 316 - Fuel Pump Re-Wire

Or should I be following this one instead?

RDR 3000GT/Stealth Fuel Pump Rewiring

Cheers,

Joe

soccermania688 · 07-18-2010, 08:33 PM

What i did was run a 10 awg wire from the battery to the pump. using a regular 30a automotive you use the stock fuel pump power wire as your relay trigger. you also need to do the resistor by-pass. The stock wires are very small and go a long distance so there really isn't enough power getting to the pump under stock wiring. I can't feel the transition from low speed to high speed anymore and its a lot smoother.

If you ever upgrade your pump you might over run your stock fpr and then all you would need is an aftermarket fpr. I don't think a walbro would overrun the stock fpr if its still in good conditon

GTOJOE · 07-18-2010, 09:17 PM

Have you noticed any issues with fuel pressure? Should I be also fitting an aftermarket FPR?

soccermania688 · 07-18-2010, 10:03 PM

Quote:

Originally Posted by GTOJOE

Have you noticed any issues with fuel pressure? Should I be also fitting an aftermarket FPR?

Its not necessary with the stock pump. Fuel pressure seems fine but I don't have a gauge on it.

x2xtreme360 · 07-18-2010, 10:15 PM

I just did this yesterday... so it's funny to me that this thread pops up

My fuel pressure has been high for awhile. I already had the resistor bypass mod done. Here are my before and after numbers.

BEFORE:
11.23V Cold idle
10.76V Under boost
11.07V Hot idle

AFTER:
13.91V Cold idle
13.96V Under boost
13.95V Hot idle

Battery voltage: 14.09V

Obviously, the mod kept the fuel pump voltage very stable. Before it was done, voltage would DROP when it was needed most... under boost.

I ran 10AWG from the battery back to the pump. I thought about using 8AWG but went with 10 because Hosfelt didn't have 8AWG and they were VERY cheap. My install is VERY clean and I am quite satisfied with the results.

Fuel pressure is even higher now at around 50psi. Coming up next for me is an AFPR. On the plus side, my injectors flow more at 50psi... so I might even be able to go higer than 14psi of boost.

BTW, the Erik Gross method isn't the way to go... even he himself has stated high fuel pressure after doing it his way.

GTOJOE · 07-18-2010, 10:22 PM

Thanks for the update. I will be using 8 guage wire. My main concern was the high FP. But if it doesn't cause issues I'll go ahead with it.

Cheers,

Joe

Ferriolom · 07-18-2010, 10:25 PM

I did the rewire in may with a 40amp relay. I have sufficent amps to the fuel pump.
Running a 255 without an FPR (I need one like Xtreme does)
kwikwire.com sells a kit for this for like $25 if you don't want to do it custom tho..

x2xtreme360 · 07-18-2010, 10:26 PM

Quote:

Originally Posted by GTOJOE

Thanks for the update. I will be using 8 guage wire. My main concern was the high FP. But if it doesn't cause issues I'll go ahead with it.

Cheers,

Joe

You will probably have higher fuel pressure... as I said, mine is at 50psi right now when it should be at ~38psi at idle.

Ferriolom · 07-18-2010, 10:28 PM

Depends. I don't think you will overrun the stock FPR with a rewired stock pump will you? With a 255 you NEED an AFPR though...

GTOJOE · 07-18-2010, 10:39 PM

I'm running stock boost [with free boost mod] atm and don't intend on increasing it until I have a Walbro 255. In this case I would fit an aftermarket FPR at the same time. Depending on finances I might fit the FPR sooner rather than later.