Settings for Return Style Fuel System

[CrankyVet]

I'm in need of some guidance on what changes I need to make in the ECM to run a return style fuel system.

This is a stock daily driver 2014 Silverado 1500 with L83. I've a Edelbrock 2300 supercharged 5.7L on the stand that I'll be dropping in at a later point. Because my engine install includes an interchiller system, new dual exhaust, new low-side fuel system, etc., if I were to install it all in one go I think it would take about a week doing it mostly by myself. However, I can't dedicate a full week due to work commitments so I'm trying to get as much knocked out as I can before I drop in the engine.

With that said, I have a Snow dual pump return style fuel system that I plan on installing first but can't find any information on what changes in the tune are required. I'll have my truck professionally tuned once everything is installed.

I appreciate any insight you folks could provide and I'm happy to answer any questions you have.

Thanks - CV

[gtstorey]

By return style are you talking vacuum/pressure referenced? If so, how does that work with direct injection?

[GHuggins]

You're basically taking the place of the. fpcm I assume? Cause it's going to do the exact same thing. Every one of these I've ever done were in swaps and had the fpcm removed. Otherwise you could just upgrade the stock pump and have a second come on with CAN like the Dstek or a Hobb's switch just in boost. You didn't mention boost goals or injectors/fuel plans

Make sure since you're running a PD blower on a truck that you install a sciap and a lt4 map and wire the temp into pin 1 of the MAF wire. Of course removing the MAF temperature from the equation by cutting it or installing the jumper harness. That's if you want complete throttle control with it being a truck and possibly keep variable cam timing which I highly recommend.

[CrankyVet]

By return style are you talking vacuum/pressure referenced? If so, how does that work with direct injection?

Correct. I won't be using PWM pumps so I'll be using a boost referenced external regulator. Since information is pretty sparse on this, I'm not really sure if boost referenced pressure is needed as long as the high pressure pump is getting 70-75 psi.

[gtstorey]

If this is just using a reference pressure to cut on a second pump, I guess that maybe makes sense. But increasing pressure by 20 psi at the low side of the high pressure pump and bumping the pressure on the high side from 2000psi to 2020psi doesn't seem like it would make any real difference.

[GHuggins]

Main benefits would be if setting the pressure lower and letting what little vacuum there is still pull low side down to 45psi. This spreads out pulsewidths at cruise and idle more helping to stabilize things even on the DI setups I've messed with this on of course you have to set high side around stock values too. Guess it also helps hpfp rail pressure control with pressure being lower? Then boost will get it up to the 70 or 75 psi to help the high side keep up. Only so much will flow through the high side pump, but at least the capability is there. You just have to make sure to set it up to not be equipped with the fpcm and delete all of the low side associated codes for it. I do recommend plumbing in the low side pressure sensor. It should be going straight to the ecm on these, but now that I'm thinking about it I'm not 100% sure. Pretty sure as I remember some of the deletes showing low side. You're essentially just taking the place of what the fpcm is already doing. That's your end goal...

[CrankyVet]

Greg - That's correct, essentially bypassing the FPCM and using non-PWM pumps. My 2nd pump will be wired to a Hobbs switch. I'll be running my little stroker at 10-12 psi on E65 and 93 but I know there will come a point in time when I'll turn it up. Everything that's being done is to support future power goals with the exception of the HPFP and injectors which are both LT4 pieces.

Thanks for the tips on sensors and wiring but I'm not sure what "sciap" is. The cam is custom spec'd non-VVT.

So if I'm picking up what you're putting down, you don't make any changes in the tune to run non-PWM pumps with a static fuel pressure?

[GHuggins]

Super Charger Inlet Air Pressure sensor

https://forum.hptuners.com/showthrea...kground-Tables

And no, just set it to not have the fpcm and set your high side settings accordingly.

[CrankyVet]

Thanks for the help Greg.

[Estep40511]

I'm in need of some guidance on what changes I need to make in the ECM to run a return style fuel system.

This is a stock daily driver 2014 Silverado 1500 with L83. I've a Edelbrock 2300 supercharged 5.7L on the stand that I'll be dropping in at a later point. Because my engine install includes an interchiller system, new dual exhaust, new low-side fuel system, etc., if I were to install it all in one go I think it would take about a week doing it mostly by myself. However, I can't dedicate a full week due to work commitments so I'm trying to get as much knocked out as I can before I drop in the engine.

With that said, I have a Snow dual pump return style fuel system that I plan on installing first but can't find any information on what changes in the tune are required. I'll have my truck professionally tuned once everything is installed.

I appreciate any insight you folks could provide and I'm happy to answer any questions you have.

Thanks - CV

Can I ask what kind of rods and crank you used for your stroker? Ive been wanting to do this to my L83 this winter. Was going to get a Reman L86 from work (GM), but with all the main bearing issues and failures, I think Ill keep my engine thats in my truck lol.