I never thought this day would come, thanks to HPT they added support for Fuel Pump Control Module... now time for questions.
FIRST OFF: YOU WILL NOT BE ABLE TO READ YOUR CURRENT (or edited/flashed) FPCM FILE. HPTUNERS software will supply a stock file for you to edit and incorporate into your original HPT Tune. You make edits to this tune, and flash this to your FPCM.
I wanted to get dual pumps and run it with the ZL1 controller which is the same as a SS controller but a different OS on it.. SS fuel pump itslef limits fuel pressure at 58psi (via built in regulator) but the FPCM is programmed to start reducing fuel pressure below 58psi at a around 160lb/hr Fuel Flow as told to do by the settings in the Max Desired Pressure table in the FPCM - log "Desired Fuel Pressure" to see what pressure the FPCM is trying to achieve. With a MSD BAP, The SS Pump does not appear to be weak, it is actually holding exactly the same PSI that the "Desired Fuel Pressure" is asking for. The Desired Fuel Pressure is set in the "Maximum Desired Pressure" table in the FPCM! Stock, the SS FPCM is slowing down the pump starting around 160lb/min according to the "Instantaneous Fuel Flow Estimate" PID. ZL1 asks to hold 450 kpa (68psi ish) the entire time.
So for scanner you need to add these (from the FPCM section) if you dont have them already:
1) Fuel Pressure
2) Instantaneous Fuel Flow Estimate (lb/hr) - this is the flow data that shows in the top row of MAX PRESSURE table in FPCM
3) Fuel Pump Commanded DC
4) Desired Fuel Pressure - this should also match the data in the MAX PRESSURE table accoring to what ever Fuel Flow your at
5) Fuel Pressure
6) Fuel Pump Trim Short Term
7) Fuel Pump Trim Long Term
What you should see is your Desired Fuel Pressure should always match your Fuel Pressure. Desired fuel pressure is what the FPCM is trying to supply by modulating the Fuel Pump via PWM. I thought I had weak pump and losing fuel pressure but I'm not.. my stock FPCM MAX PRESSURE table reduces pressure as FLOW RATE increases, for whatever reason. Maybe to save the pump. My Boost A Pump is adding voltage to allow it to have more power/rated flow, but the FPCM is still modulating it, at least in the non-boost areas. I need to read up on my MSD BAP and see exactly how it works.. does it just increase voltage or is it also modifying the PWM signal (increasing Duty Cycle)... hopefully not.
To make changes (increase pressure or tell the pump to generate more flow):
Max Desired Pressure: In my stock file the generated logged fuel PSI matches this table 100%. If I want more pressure for given flow, just up this table across the board (tested up to 100kpa 58psi - same as my fuel regulator... beyond this is wasted energy). Lowering values in this table generates lower running and logged Fuel Pressure. I had it as low as 16psi running fine. Maybe I could go lower. Changing just the first few cells to low numbers created a situation where idle was at 20psi and anything higher than that was normal 58psi.
To fix my loss of fuel pressure above about 3500rpms (160lb/hr fuel flow on my setup) I simply changed my decreasing "Maximum Desired Pressure" table to all 400kpa (58psi) and it holds 58 psi now! I only ran it to 5000 RPM but it used to start dropping at 3500 RPM stock settings, now rock solid 58 psi past 5000rpm. Haven't taken it all the way up yet. I'll probably blow my pump out that's fine
-----Parameter Descriptions-----
Engine:
Max Engine Boost (current populated with all 0's)
Injectors: (These seem to match my stock 2010 Camaro LS3 settings, my ECU tune still shows my Whipple settings). Description for these say they are duplicates of the ECU with same name, but they are not really since they are the old stock values.
Flow Rate vs Press: Obvious... but is there any need to change these. They dont appear to be linked to anything in the ECU.
Min INjector Pulse: Obvious... but is there any need to change these? They dont appear to be linked to anything in the ECU.
Pressure:
Min Desired Pressure: Min is 45psi. Not 100% sure what this does other than set the minimum possible fuel pressure.
Max Desired Pressure: It's an Estimated Fuel flow table.. in scanner you need to log "Instantaneous Fuel Flow Estimate". In my stock file the generated logged fuel PSI matches this table 100%. If I want more pressure for given flow, just up this table across the board (need to test this). Lowering values in this table generates lower running and logged Fuel Pressure. I had it as low as 16psi running fine. Maybe I could go lower. Changing just the first few cells to low numbers created a situation where idle was at 20psi and anythnig higher than that was normal 58psi.
Regulation Pressure: This flow vs batt voltage table is all set to 65psi (450kpa).
Fuel Pump: I assume this has to do with dialing in the PWM power to the fuel pump.. if I have two pumps installed then maybe I want to tweak "Openloop DC and Min DC", by lowering the numbers by roughly 25%?
Openloop DC:
Openloop DC Mult:
Min DC:
2010 Camaro LS3 Stock FSCM 1.PNG
2010 Camaro LS3 Stock FSCM 2.PNG
EDIT:
I am seeing increasing FP beyond 58psi with the stock pump and MSD Boost A Pump with 10psi boost, using 58psi (400kpa) in Max Pressure table. I should probably reduce this table to 380kpa to stay below the pump regulator of 58psi:
Stock FPCM Settings with MSD BAP:
rpm------Fuel psi/desired-------Inj DC-------Pump DC
5000-----48/50-------------------60----------81.6
6000-----46/48-------------------73----------91.4
400kpa Fuel Pressure flat across with MSD BAP
5000-----57/58-------------------54----------85.9
6000-----61/58-------------------60----------95.0
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EDIT 8-21-2017: Added some E85 and ended up with 40% according to the sensor..
The max % Ethanol you can run with stock LS3 Whipple Injectors with MSD BAP and stock pump, stock exhaust and cam appears to be 40%.
Fuel pressure started at 53-54psi (commanded 55psi) near 6000rpm and dropped to 42psi by 6500rpm. Once the FPDC hit 100%, fuel pressure started dropping so that's a nice correlation. Still, AFR was solid and on target.