Nnbs return fuel system wiring fpcm
 

Getting ready to convert to return set up on my nnbs truck. I have the shaved truck intake and want to run btr fuel rails or on3 has a whole fuel kit with reg and everything for good price.Plan is single e85 compatible 450,80# and 600hp for now. What’s everyone that has done the return swap doing for the wiring? I want to just buy a fuel pump relay hot wire kit so it’s plug and play essentially and getting power from my alt. How do I delete the stock fuel setup and the fpcm? Do I tune it out or delete it completely? I don’t want to mess with anything else if it effects the computer of some sort or car. Anyone have experience with this? I’ve looked and nothing really on the wiring except the fuel pump relays seem the easiest cleanest route. Just need to know about stock fuel setup and what to do with it after I go return setup. Thanks

Im still trying to figure it out for my dual 450's.
I bought the painless hot wire kit, one for each.
Im gonna try tapping into the FPCM to avoid the CEL and losing remote start, but if all else fails ill just hot wire it straight to the pumps, and HP tuners lets you tune out the FPCM completely, just gotta buy the extra credits.

Ok that’s what I was hoping for. As long as my tuner can time it out so I don’t get a cel. I don’t have remote start so I can careless about that feature. They make fuel pump relay kits for up 2/3 pumps. On3 has it if you haven’t gotten both already. Keep me posted on how you went about yours and pictures of you have any would be appreciated. Maybe this can be a sticky when all said and done for nnbs return setups for big hp

yeah i found out about the plug and play units too late.

I think i can get the Hot wire kits to work anyways. Ill keep you posted though

This is what I did for my 525 pump. Bought a spal HO fan relay as it can handle the amperage better than any other relay on the market, used 30 amp large blade fuse (based on amp draw ) and 8 gauge wiring to the pump connected via a 280 series harness that turns into ptfe 10 gauge wiring to the pump. The relay is controlled via fuel pump wire (gray wire off red block). Now I don’t have a fpcm but this is just another option. I run dual spal HO fans and they have high amp draw and destroyed every relay I could find until I did their kit. They run 50$ Per relay FYI

If thisbroute works and is cheaper then I’m all for it. Rather not drop $100 plus on a fuse block for one single pump. All nnbs don’t have the fpcm? Is it just the flex fuel trucks that had them? Thought all nnbs went to the fpcm near spare tire. Guess not. How’s your fuel and pump holding up? I like the 8awg to 10awg to the pump. I was going to run #10 all the way

Mines not flex fuel but i have an FPCM.. i think it started with the 6l80, some NNBS trucks still had the 4l60

Well with the way I did my setup you wouldn’t use the fpcm. The fuel pump will see a continuous 14.4 volts (or what your battery/alt is holding) the only thing from the original fuel system used is the fuel pump power wire from the fuse block in the engine bay to trigger the relay and original feed line as return. https://www.holley.com/products/cool...parts/HO-RELAY
https://www.carid.com/install-bay/4-...CABEgJy_vD_BwE

yea that’s what I was expecting. I’ll just have to tune out the fpcm I guess? Can you text me pictures of your setup? Looks like I’m doing a very similar build to yours.i think I hit you up before about the hellcat pump and you made its own housing? 6502189005

thanks Kevin

I will. Send some pics. I’m taking the pump out this weekend to change out the Venturi to a larger one from radium engineering. Less than 1/4 tank causes too many fluctuations at full throttle.