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Thread: FSCM (FPCM) Tables/Settings - 2010 Camaro LS3 vs ZL1

  1. #181
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    my setup is a custom swap, im not out of pump, truck is running great, i used a ZL1 PCM as a base, my fuel setup is a walbro 450 intank, with a relay, it is working perfectly, i just recently added the FPCM so i can log Fuel pressure and to let know the PCM the actual fuel pressure,(FPCM isnt wired to the pump, im not loosing fuel pressure, my question is if i need to populate the flow rate VS press flat or upward form?

  2. #182
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    Quote Originally Posted by castorjames View Post
    my setup is a custom swap, im not out of pump, truck is running great, i used a ZL1 PCM as a base, my fuel setup is a walbro 450 intank, with a relay, it is working perfectly, i just recently added the FPCM so i can log Fuel pressure and to let know the PCM the actual fuel pressure,(FPCM isnt wired to the pump, im not loosing fuel pressure, my question is if i need to populate the flow rate VS press flat or upward form?

    tried the sloped calibration and my fuel went lean, inj delta pressure was at like 511 at idle, changued FPCM fitted to YES and now inj delta pressure at idle is 401-418kpa and my fuel trims are close to 0 now.

  3. #183
    fpcm comunication plays a pretty big role as you just found out. someone else was talking about pressure drop to 20 psi wihich is supper low

  4. #184
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    Is it possible to change a 2010 Camaro SS fpcm to not have such a large pressure drop? With e85 my pump drops something like 20 psi at redline. Duty cycle is over 100% with the 50lb/hr truck injectors so I try to keep it around e50-60.

  5. #185
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    Quote Originally Posted by xc_SS/RS View Post
    Is it possible to change a 2010 Camaro SS fpcm to not have such a large pressure drop? With e85 my pump drops something like 20 psi at redline. Duty cycle is over 100% with the 50lb/hr truck injectors so I try to keep it around e50-60.
    yes, that's the whole point of this thread.
    2010 Camaro LS3 (E38 ECU - Spark only). MS3X running complete RTT fuel control (wideband).
    Whipple 2.9L, 3.875" Pulley, kit injectors, supplied MSD Boost-A-Pump, stock pump
    LG Motorsports 1 7/8" Headers - No Cats, stock mid pipe with JBA Axle Back
    ZL1 Wheels/Tires

  6. #186
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    Quote Originally Posted by 10_SS View Post
    yes, that's the whole point of this thread.
    Alright I wasn't sure if it was only for people with boost so I'll do some reading. Gracias homie

  7. #187
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    Quote Originally Posted by xc_SS/RS View Post
    Alright I wasn't sure if it was only for people with boost so I'll do some reading. Gracias homie
    should be based off the Fuel Flow Rate, nothing else. Been awhile I dont remember if you can log that PID. The stock SS FSCM starts dropping pressure at the higher flow rates for whatever reason. I've been running my stock pump and modified table in the FSCM with a BAP, no problems with anything. Put the next smaller pulley and long tubes on, FP is still rock solid.
    2010 Camaro LS3 (E38 ECU - Spark only). MS3X running complete RTT fuel control (wideband).
    Whipple 2.9L, 3.875" Pulley, kit injectors, supplied MSD Boost-A-Pump, stock pump
    LG Motorsports 1 7/8" Headers - No Cats, stock mid pipe with JBA Axle Back
    ZL1 Wheels/Tires

  8. #188
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    Great thread!

    So, I've been dealing with my pump DC not being high enough to support the fuel demand for a 427 with a 1.9L at 1/2-3/4 throttle. When I'm at 3/4 throttle my pump duty cycle is in the 55-65% range and my fuel pressure drops to low 60psi, which causes me to run lean under boost (.86L). Once I floor it and my DSX Aux pump kicks in, my fuel pressure holds steady at 70-72psi and fueling is good (.78L).

    At first I thought it was my MAFF table, but the same HZ in a higher gear at WOT, fueling was spot on. It was only lean when I was at 3/4 throttle and my pumps duty cycle was lower than 100% and pressure was lower than commanded.

    Good news is I was able to fix my WOT pump fueling. When the DSX Aux pump kicked in, I was hitting my high limits and the FPCM was dialing back my stock pumps duty cycle from 100% to 50%.....this was horrible as it probably cost me an engine last fall and was still causing issues with my new engine. Since then I increased the high flow tables and now my duty cycle is no longer killed when the DSX Aux kicks in.

    My only issue now is getting the stock pumps duty cycle to come up a little sooner since this engine has a lot more fuel demands at part throttle.

    Do you think I should increase the open loop duty cycle table? Thanks for sharing this info, it's helped out a lot.

    v/r

    Jason

  9. #189
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    Quote Originally Posted by 10_SS View Post
    should be based off the Fuel Flow Rate, nothing else. Been awhile I dont remember if you can log that PID. The stock SS FSCM starts dropping pressure at the higher flow rates for whatever reason. I've been running my stock pump and modified table in the FSCM with a BAP, no problems with anything. Put the next smaller pulley and long tubes on, FP is still rock solid.
    Yeah I set it to all 400 kpa and it will now hold full pressure with gas, but with anything above E40 the fuel pump can't keep up anymore. It's too old so I'm looking at either a livernois Firestorm dual pump or a ZL1 pump.

    I've got the livernois pump on hand, but have no clue if I need to change any settings beyond fuel pressure on the fpcm. Looks like nothing else, but livernois say there's some tuning needed so the ZL1 pump looks like a easier option. And the CTS-V fpcm has different settings so I'm worried it won't work right.

  10. #190
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    Quote Originally Posted by Jason Austin View Post
    Great thread!

    So, I've been dealing with my pump DC not being high enough to support the fuel demand for a 427 with a 1.9L at 1/2-3/4 throttle. When I'm at 3/4 throttle my pump duty cycle is in the 55-65% range and my fuel pressure drops to low 60psi, which causes me to run lean under boost (.86L). Once I floor it and my DSX Aux pump kicks in, my fuel pressure holds steady at 70-72psi and fueling is good (.78L).

    At first I thought it was my MAFF table, but the same HZ in a higher gear at WOT, fueling was spot on. It was only lean when I was at 3/4 throttle and my pumps duty cycle was lower than 100% and pressure was lower than commanded.

    Good news is I was able to fix my WOT pump fueling. When the DSX Aux pump kicked in, I was hitting my high limits and the FPCM was dialing back my stock pumps duty cycle from 100% to 50%.....this was horrible as it probably cost me an engine last fall and was still causing issues with my new engine. Since then I increased the high flow tables and now my duty cycle is no longer killed when the DSX Aux kicks in.

    My only issue now is getting the stock pumps duty cycle to come up a little sooner since this engine has a lot more fuel demands at part throttle.

    Do you think I should increase the open loop duty cycle table? Thanks for sharing this info, it's helped out a lot.

    v/r

    Jason
    What car, and what fuel pump?

  11. #191
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    Quote Originally Posted by xc_SS/RS View Post
    What car, and what fuel pump?
    Yeah, that info would probably help a bit.

    It's a CTS-V with stock in tank twin pumps. I actually just experimented with adding 20% to the open loop duty cycle tables and that fixed my issues with the DC staying low when i'm part throttle. It's actually a bit to much. I'm going to reduce it to 15% over stock for the higher flow cells. The 20% had me hit 100% duty cycle at 50% throttle. I can see in my log, my fuel pressure spikes to 76psi and pressure releases through the bypass valve (i'm assuming) and then pressure stabilized in the 69-72 psi range, which is what is commanded.

    Thanks again to this thread....pretty bad ass.
    Attached Images Attached Images
    Last edited by Jason Austin; 09-16-2019 at 07:03 PM.

  12. #192
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    Larger cube FPCM settings

    To get my FPCM to not dial my stock pumps back when my aux pump kicks in, this is what I've done to my FPCM settings. FYI, this is a 7.0L CTS-V with an LSA 1.9L blower making 12PSI. Stock in tank pumps and a DSX Aux pump module. E-85 and ID 1300X injectors.

    Notice the High Flow tables. These tables tell the FPCM to bring down the fuel pump duty cycle if a certain pressure is reached. If you have an aux pump kit, you more than likely need to increase these (reference attachment) to keep your FPCM from dialing back your fuel pumps under WOT.

    Just wanting to share.....tired of seeing people hack up their aux pump kits and running lean under WOT.
    Attached Images Attached Images

  13. #193
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    Bringing this thread back from it's dormant state. I'm still trying to understand what I might be doing wrong here. It's almost like my aux pump is kicking in slow or something (see pic). It happened similarly in two spots where I went WOT both times. Pressure would rise, but then fall. After a couple seconds, pressure would shoot back up again.

    I've adjusted my high flow tables so that pump DC under boost holds 100%. Could it be that my Hobbs switch (4psi) is THAT slow? Also, is anyone running a check valve to their aux pump? I decided to put one in my system to keep the "standard" pressure from pushing on/through the aux pump. Could that be the issue?

    Any help is appreciated.

    I'm attaching the tune. The log for this screenshot is too large to load.

    WOT Fuel Pressures.JPG
    Attached Files Attached Files

  14. #194
    What pump are you using, the 255 external? I have built several Camaro aux pump setups, I run a 2psi hobbs just to make sure it comes on early enough, along with an indicator LED so I know when it switches on, and have mounted a test/override button as well. Never had anything noticable enough to cause a concern with going lean, and I havent ran a check valve. If anything I get a small rich spike while the FPCM compensates for the additional pressure. You could also move the pressure sensor to the rail from back by the tank.

  15. #195
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    I'm running the DW 350il pump. I can see about running a 2psi Hobbs to try to get it on a little sooner. Running a switch and LED might be a bit of a pain. I've had a hard time finding good places to get into the cab with wiring.

    The other easy thing to try would be to bypass the check valve also. There could be some weird pressure fight going on there. I just wasn't sure if it was needed so that fuel didn't push back through the pump all the time.

    Thanks for the fast feedback!

  16. #196
    No problem. A check valve lowers flow at all pressures (I used to work in the valve engineering industry) but it may not be enough to cause what you are seeing. I ran my wires from the relay and Hobbs I mounted where the cabin air filter is, there is a relatively easy wire pass through there.

  17. #197
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    I haven't been into the cabin filter yet but I have plans to, so I'll check there. Thanks

    Also, I'm wondering if there's a pressure battle at the check valve. I think it needs to see a differential of around 4psi also to open. If my stock pump turns up, it could cause a delay before the other pump builds enough pressure to kick the valve open.

  18. #198
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    Does anyone know how the Hot Fuel (ECM 17025) and the Hot Fuel Soak ((ECM 17026) work? The description on the first says "If the fuel pressure drops below this the Hot Fuel conditions are set, and this fuel pressure is commanded when vehicle speed is less than Hot Soak VSS." Attached is a screen shot of my chart. Per the description, if the actual fuel pressure dropped below 300 kpa at any temp up to 132F, it would then command 300 kpa? That just doesn't make sense. It is almost as if there should be another setting for the pressure threshhold?

    I recently have an issue where my commanded fuel pressure drops, IN THE MIDDLE OF A WOT PULL, for no apparent reason. It did not do this in the past, the only thing I have changed was to clear the fuel pump trims with a GM scan tool. LT pump trims have been a steady 1.13, and ST have varied. I put that 1.13 increase into the Openloop DC chart as well. Regardless, this should not have changed the commanded pressure to suddenly drop. Attached graph it is at the point where commanded fuel pressure goes from 400 to 300 kpa, while I am still stepping into the throttle. Then the pump duty cycle drops like a rock as it starts toward 300 kpa, but slowly recovers to massively overshoot. At the cursor point, it should be on its way to commanding 450 kpa.

    My fuel flow/pressures are:
    low flow <25 lb/hr = 300 kpa
    normal flow 50-100 lb/hr = 375 kpa
    high flow >100 lb/hr = 450 kpa

    I do not see anything in the scanner to monitor hot fuel to know if this is what is occurring? As I mentioned, the only thing that I really changed was the clearing of the fuel pump trims, which shouldn't affect the commanded fuel pressure drop. Vehicle has a Gen4 stock 6.2L with a Whipple.

    hot fuel chart.JPG commanded fuel pressure drop.JPG

  19. #199
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    Update to the above. I logged again while monitoring Fuel Pressure State, during the drop in commanded pressure under WOT it is changing from High Flow to Low Flow state. At the same time, Instantaneous Fuel Flow Estimate goes to 0, while Advance Fuel Flow Estimate keeps climbing, albeit always lagging Instantaneous. I even put back to stock, an oddity with the chart ECM 17015 under Fuel System/General/Desired Flow/Fuel Flow-Airflow. They had all 1's except for at fuel mass 480 and 640 mg, which were 0. Thought there may be some hidden charts that was being compensated for here, which is why I had put them all at 1 some time ago (not correlated with this issue, but did so just in case). I do not know how the LT fuel pump trim works, but since resetting it has stayed at 1.0 for several drive cycles. It still should not affect the commanded state/pressure.

    I am about to put 450 kpa across the board everywhere, all the time, before something gets hurt. Just don't understand why it is going to Low Flow like this when I never saw it do so before. Cal and log are attached. WOT pressure drop at 11:32 in log. It also went from Low Flow to Cold Engine right before in this instance.

    yukon - 182 - FULL MAF.hpt182 hot start.hpl

  20. #200
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    Update. The cause was from trying to use Cylinder Gain, despite the warnings of high rpm problems on "some" operating systems. Apparently mine is one of them, 12656198. I had tried adjusting 2 of the cylinders by just 1% for starters. When I did this just happened to be one cal iteration from when I cleared the fuel pump trims. I went back through my logs and found it occurring on one just before I cleared the trims, though I did not catch it as it was only in one spot.

    I put the Cylinder Gain back to Disable, and fuel pressure is commanding and following as it should.