GenIV pump/FPR work around?
Thread Starter
Staging Lane
Joined: Mar 2016
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GenIV pump/FPR work around? Subject is an e85 only turbo street truck (2012 LS 4,8) that I plan to drive alot My tuner says once I convert to a return-style fuel system, I will forever have a CEL light, And converting to return style seems to be required for most of the in tank pumps- he also also says I can NOT run a stand alone fuel system while using the factory ECM.This sucks because I have a sumped fuel cell, lines and a beefy pump already from another e85 project..
Since the factory system is return less and with an intank pump and FPR that is controlled by the ECU- could I just install a 2 port fuel pressure regulator or Y-block/check valve) on the factory fuel line AFTER the fuel tank, then feed the other FUEL IN port with my existing e85 system, and then just run the lines and rails I need for my HP goals?
Or even just run the damn factory pumped and regulated line straight into my fuel cell basically combining the two like a long range tank?
Since the factory system is return less and with an intank pump and FPR that is controlled by the ECU- could I just install a 2 port fuel pressure regulator or Y-block/check valve) on the factory fuel line AFTER the fuel tank, then feed the other FUEL IN port with my existing e85 system, and then just run the lines and rails I need for my HP goals?
Or even just run the damn factory pumped and regulated line straight into my fuel cell basically combining the two like a long range tank?
I have a GMPP factory computer and I have a return style system running 2 - 450 LPH in-tank pumps. The first one is run off the computer, the second one is run off a relay from a Hobbs switch. It goes pump, filter, rail, fuel pressure regulator mounted on the rail, and return back to the tank. I could run the first pump without the computer also, but I like the 3 second prime option.
Thread Starter
Staging Lane
Joined: Mar 2016
Posts: 64
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I have a GMPP factory computer and I have a return style system running 2 - 450 LPH in-tank pumps. The first one is run off the computer, the second one is run off a relay from a Hobbs switch. It goes pump, filter, rail, fuel pressure regulator mounted on the rail, and return back to the tank. I could run the first pump without the computer also, but I like the 3 second prime option.
My idea wont work- there is a fluid pressure sensor further down the lie> even though the FFV pumps pretty much stay at 61psi, if that pressure sensor doesn't communicate with the PWM then I get a CEL. I did find a work around, but even after repinning and cutting the FPCM out of the loop, ill need HP Tuners to clear the resulting codes.
Last edited by deucesallin; Jul 25, 2019 at 09:04 PM.
Thread Starter
Staging Lane
Joined: Mar 2016
Posts: 64
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He says he can only go from "variable" to "fixed" on the "FPR."
Unless your talking about one of the pin-out methods ive read about on HP Tuners boards and Gearhead EFI, that BOTH INVOLVE two specific DTC's despite removing the FRP/PWM from the system...
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Staging Lane
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Launching!
Joined: Dec 2011
Posts: 230
Likes: 73
From: south florida
in my truck i left the stock fuel system alone, sumped the stock tank with a magnafuel 750.
under the hood grabbed the stock fuel line>flex fuel sensor>check valve>fuel pressure regulator.
when i had it set it up on the stock fuel rail, the magnafuel went into the fuel pressure regulator as well - with its own check valve, and had a single line off of fpr to the fuel rail. now the magnafuel goes to holley rails and then goes to fpr, stock line still straight to fpr. regulator is set above where the stock pump would never crack it open
did it on mine cause i didnt feel like hearing a large pump all the time, its on a 3psi hobbs switch. the stock flex fuel pump seems to support about 550ish on its own.
2012 yukon denali turbo, e38 pcm/fpcm, stock flex vehicle
under the hood grabbed the stock fuel line>flex fuel sensor>check valve>fuel pressure regulator.
when i had it set it up on the stock fuel rail, the magnafuel went into the fuel pressure regulator as well - with its own check valve, and had a single line off of fpr to the fuel rail. now the magnafuel goes to holley rails and then goes to fpr, stock line still straight to fpr. regulator is set above where the stock pump would never crack it open
did it on mine cause i didnt feel like hearing a large pump all the time, its on a 3psi hobbs switch. the stock flex fuel pump seems to support about 550ish on its own.
2012 yukon denali turbo, e38 pcm/fpcm, stock flex vehicle
Last edited by randeez; Jul 27, 2019 at 06:38 PM.
Staging Lane
Joined: Mar 2016
Posts: 51
Likes: 1
It is not a flex fuel. Though I now have a sensor and can switch back and forth between 93 and E85.
Software used is EFILIVE. I know there is a parameter for FPCM Fitted which was changed to NO. The FPCM is still plugged in so I don't get the communication codes.
You could start a thread in the Tuning/Diagnostics section. It might get you some more direct suggestions as to what exactly has to be turned off, EFILIVE and HPTuners.
Software used is EFILIVE. I know there is a parameter for FPCM Fitted which was changed to NO. The FPCM is still plugged in so I don't get the communication codes.
You could start a thread in the Tuning/Diagnostics section. It might get you some more direct suggestions as to what exactly has to be turned off, EFILIVE and HPTuners.
Thread Starter
Staging Lane
Joined: Mar 2016
Posts: 64
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[QUOTE=Longblue;20129183]It is not a flex fuel. Though I now have a sensor and can switch back and forth between 93 and E85.
Software used is EFILIVE. I know there is a parameter for FPCM Fitted which was changed to NO. The FPCM is still plugged in so I don't get the communication codes.
You could start a thread in the Tuning/Diagnostics section. It might get you some more direct suggestions as to what exactly has to be turned off, EFILIVE and HPTuners.[/QUOTE
Only FFV have the Fluid Pressure Sensor, which Randyeez system seemed to defeat.
Software used is EFILIVE. I know there is a parameter for FPCM Fitted which was changed to NO. The FPCM is still plugged in so I don't get the communication codes.
You could start a thread in the Tuning/Diagnostics section. It might get you some more direct suggestions as to what exactly has to be turned off, EFILIVE and HPTuners.[/QUOTE
Only FFV have the Fluid Pressure Sensor, which Randyeez system seemed to defeat.
Launching!
Joined: Dec 2011
Posts: 230
Likes: 73
From: south florida
I left the low demand setting at 43.5psi or whatever , high demand is flatlined at 61psi in the fpcm. So low demand it will just act like non return system.
Fpr is set at around 60psi also, so that the fpcm just thinks that it keeps up and doesnt care about the secondary pump, all injector data in tune is left alone (scaled 1200cc fic's).
It doesnt like boost referencing the fpr though, not sure if the fpcm makes corrections off the map sensor or something. has worked fine for a few months
Ithough about moving the pressure sensor to the fpr to get an accurate reading , but I havent really had any problems with it as is. Right now if the fpr is higher than stock feed it would close that check valve and pressure reading wouldnt be right, that could correct boost reference but not worried about it with power level right now they flow plenty
Fpr is set at around 60psi also, so that the fpcm just thinks that it keeps up and doesnt care about the secondary pump, all injector data in tune is left alone (scaled 1200cc fic's).
It doesnt like boost referencing the fpr though, not sure if the fpcm makes corrections off the map sensor or something. has worked fine for a few months
Ithough about moving the pressure sensor to the fpr to get an accurate reading , but I havent really had any problems with it as is. Right now if the fpr is higher than stock feed it would close that check valve and pressure reading wouldnt be right, that could correct boost reference but not worried about it with power level right now they flow plenty
Last edited by randeez; Jul 28, 2019 at 12:16 PM.
Thread Starter
Staging Lane
Joined: Mar 2016
Posts: 64
Likes: 0
Perfect. in my truck i left the stock fuel system alone, sumped the stock tank with a magnafuel 750.
under the hood grabbed the stock fuel line>flex fuel sensor>check valve>fuel pressure regulator.
when i had it set it up on the stock fuel rail, the magnafuel went into the fuel pressure regulator as well - with its own check valve, and had a single line off of fpr to the fuel rail. now the magnafuel goes to holley rails and then goes to fpr, stock line still straight to fpr. regulator is set above where the stock pump would never crack it open
did it on mine cause i didnt feel like hearing a large pump all the time, its on a 3psi hobbs switch. the stock flex fuel pump seems to support about 550ish on its own.
2012 yukon denali turbo, e38 pcm/fpcm, stock flex vehicle
under the hood grabbed the stock fuel line>flex fuel sensor>check valve>fuel pressure regulator.
when i had it set it up on the stock fuel rail, the magnafuel went into the fuel pressure regulator as well - with its own check valve, and had a single line off of fpr to the fuel rail. now the magnafuel goes to holley rails and then goes to fpr, stock line still straight to fpr. regulator is set above where the stock pump would never crack it open
did it on mine cause i didnt feel like hearing a large pump all the time, its on a 3psi hobbs switch. the stock flex fuel pump seems to support about 550ish on its own.
2012 yukon denali turbo, e38 pcm/fpcm, stock flex vehicle
Questions:
1) Did you have ANY codes with either of your setups?
2) What has to be done to my fuel system to get me to the 550ish mark on 93+meth?
3) We talking FLYWHEEL or WHP? Ive read 450ish RWP is about the limit- but most people change alot of **** then so IDK exactly what the restriction is at that level.
Id LOVE to take my bone stock fuel system as far as it can, to allow me to drive this ****** while I work on my e85 system.
Last edited by deucesallin; Jul 28, 2019 at 12:25 PM.
Thread Starter
Staging Lane
Joined: Mar 2016
Posts: 64
Likes: 0
I left the low demand setting at 43.5psi or whatever , high demand is flatlined at 61psi in the fpcm. So low demand it will just act like non return system.
Fpr is set at around 60psi also, so that the fpcm just thinks that it keeps up and doesnt care about the secondary pump, all injector data in tune is left alone (scaled 1200cc fic's).
It doesnt like boost referencing the fpr though, not sure if the fpcm makes corrections off the map sensor or something. has worked fine for a few months
Ithough about moving the pressure sensor to the fpr to get an accurate reading , but I havent really had any problems with it as is. Right now if the fpr is higher than stock feed it would close that check valve and pressure reading wouldnt be right, that could correct boost reference but not worried about it with power level right now they flow plenty
Fpr is set at around 60psi also, so that the fpcm just thinks that it keeps up and doesnt care about the secondary pump, all injector data in tune is left alone (scaled 1200cc fic's).
It doesnt like boost referencing the fpr though, not sure if the fpcm makes corrections off the map sensor or something. has worked fine for a few months
Ithough about moving the pressure sensor to the fpr to get an accurate reading , but I havent really had any problems with it as is. Right now if the fpr is higher than stock feed it would close that check valve and pressure reading wouldnt be right, that could correct boost reference but not worried about it with power level right now they flow plenty
So with injectors and FPR tuning, the factory FFV system will support 550ish RWHP?
Last edited by deucesallin; Jul 28, 2019 at 12:40 PM.
Launching!
Joined: Dec 2011
Posts: 230
Likes: 73
From: south florida
Thanks,Randyeeez! Sounds like my idea will work I just have to plump it as you did with the pump/fpr/fps (fluid pressure sensor) inline and down stream of the rails.
Questions:
1) Did you have ANY codes with either of your setups?
2) What has to be done to my fuel system to get me to the 550ish mark on 93+meth?
3) We talking FLYWHEEL or WHP? Ive read 450ish RWP is about the limit- but most people change alot of **** then so IDK exactly what the restriction is at that level.
Id LOVE to take my bone stock fuel system as far as it can, to allow me to drive this ****** while I work on my e85 system.
Questions:
1) Did you have ANY codes with either of your setups?
2) What has to be done to my fuel system to get me to the 550ish mark on 93+meth?
3) We talking FLYWHEEL or WHP? Ive read 450ish RWP is about the limit- but most people change alot of **** then so IDK exactly what the restriction is at that level.
Id LOVE to take my bone stock fuel system as far as it can, to allow me to drive this ****** while I work on my e85 system.
no codes
i think the flex injectors are different for 5.3 and 6.2, can only really comment on the 6.2s - not sure if the in tank pumps were the same either
550 on 93+meth is probably doable but right on the edge of where injectors will be happy , and likewise 450 on e85 (about where i was with cam/fbo) started to kill injectors with them running over 90%idc to often.
i put in the larger injectors before fuel pump so i couldnt tell you what they stock injectors would do with more pressure behind them.
with stock flex pump/fic injectors it would only squeeze out a little more power before fuel pressure would nose dive.
with stock pump, 1200cc injectors - my fuel pressure would drop into the 35psi range but afrs would stay fine, so not really ideal but itll get you around. my 5900lb yukon would trap 116-118mph like that only on 6-7psi
Last edited by randeez; Jul 28, 2019 at 01:16 PM.
Thread Starter
Staging Lane
Joined: Mar 2016
Posts: 64
Likes: 0
You ran like this with the STOCK fuel system- no external FPR?