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

[mcfarlnd]

Awesome!!! Should be a 520kpa regulator internally however, the regulators are stamped with the cracking pressure on the top of them if and when you remove the pump. Was this test on a stock pump? Flex fuel or non-flex fuel? Did you raise the voltage in the table for fuel system min voltage in the ECU? That may be your reason for the drop in the higher RPM's.

[Engineer@HPT]

Some of you have asked us about the purpose of the 3 duplicate tables stored in the FPCM (and ECM in some models). Those tables, along with the Max Engine Boost (this is to determine the injector pressure drop) are used for diagnostics only, to determine min/max flow capabilities of fuel injectors. I don't know why they are duplicated when pump control is done by the ECM.

[dreksnot]

From my understanding of what's been posted, more flow out of the pump cannot be obtained, just more fuel pressure. How can this be any benefit in application? Or is this a because-we-can-do-it fix-it thing? Would it lower my IDC but still maintain the same AFR (this for that)?

[RRRocketMan]

From my understanding of what's been posted, more flow out of the pump cannot be obtained, just more fuel pressure. How can this be any benefit in application? Or is this a because-we-can-do-it fix-it thing? Would it lower my IDC but still maintain the same AFR (this for that)?

Is that true? I thought the problem was: The computer drops fuel pressure deliberately with increasing flow rate, forcing the Duty Cycle to have to increase to maintain said flow rate. At some point you hit 100% and you're maxed out on DC. If the fuel pressure didn't drop you would in fact get more flow. That's why changing the pressure table to have 4 bar straight across, regardless of flow, seems a good idea to me, as it raises the flow ceiling because now you're at 4 bar when you hit 100% DC instead of 2 bar or something like that. It's the product of pressure and duration that gives flow.

(I suspect the proof of this is HPT charging credits for FPCM access, since there's only 1 table in there worth changing lol)

Also 10_SS's experiments seem to have demonstrated a gain from making these changes.

[MikeOD]

This is the balls. I've been watching my car (2010 Camaro SS LS3) lose fuel pressure up top for 5 years and 50k miles since I did my heads and cam. I've watched it follow the IFR table every time and therefore fuel correctly, but I've always been a little nervous about the injector duty cycle. It's never been quite enough for me to decide to change a pump or control module, or add a boost a pump... But it's always been in the back of my mind as something that I didn't like.

So I just put car on my friends mustang dyno, logged a pull, flashed the FSCM with the pressure table carried across 58.5 psi instead of dropping lower, and the car held fuel pressure right through the next pull.

The PCM followed the IFR table, my final AFR didn't change at all on my wideband, but my duty cycle came down. Was worth the $50 to me for piece of mind even though the end result in my case really didn't give me anything other than that.

[GrannySShifting]

What is this buying us really, basically IF your pump setup has more headroom, you can turn the pressure up so your injectors will go further right? If your out of pump volume at 55 psi, commanding it to make 65psi will actually make pump max flow earlier? Unless the pressure limit is keeping the pump from running wide open against whatever mech reg is in the pump setup? Basically some of the factory tunes arent running the pumps wide open at full demand? Can you watch actual pump current/duty?

On the other hand, this couldnt be used say in a scenario where you put 2000cc inj in a car, and wanted to set the pressure to 30 psi to allow the pump to flow more volume at that pressure, and your way oversized injectors can still deliver enough flow - can it? Not sure how computer could make pump run 30 psi without taking power away from pump. We done that in some pump limited setups, drop fuel pressure to let pump eek by, and put lot bigger injector in it

To access this, is it $50, or $50 per car or?

[10_SS]

What is this buying us really, basically IF your pump setup has more headroom, you can turn the pressure up so your injectors will go further right? If your out of pump volume at 55 psi, commanding it to make 65psi will actually make pump max flow earlier? Unless the pressure limit is keeping the pump from running wide open against whatever mech reg is in the pump setup? Basically some of the factory tunes arent running the pumps wide open at full demand? Can you watch actual pump current/duty?On the other hand, this couldnt be used say in a scenario where you put 2000cc inj in a car, and wanted to set the pressure to 30 psi to allow the pump to flow more volume at that pressure, and your way oversized injectors can still deliver enough flow - can it? Not sure how computer could make pump run 30 psi without taking power away from pump. We done that in some pump limited setups, drop fuel pressure to let pump eek by, and put lot bigger injector in it

To access this, is it $50, or $50 per car or?

you can watch Pump DC yes right now in scanner. Current, no.

Yes on a stock return less fuel system like my 2010 Camaro you should be able to lower the fuel pressure to 30psi and hold steady at lower flow rates to make your big injectors work better since it's PWM.. On the stock SS FPSM the tuning turns down the fuel pressure at higher fuel flow rates (higher flow rates than the stock SS reaches), unsure why but they do.

Everyone would upgrade to the ZL1 FPSM module or whatever to stop this from happening. So for me and the current setup, I already had the MSD BAP and was still losing FP at WOT, but they added the FPSM PIDs to scanner and then I saw the requested FP was dropping so that meant the pump was being told to slow down... $50 basically saved me $50-150 depending what I was going to do, get a ZL1 FPSM or have mine flashed by someone. Now my FP is rock solid all the way up, but it does still need the MSD BAP or FP drops fast at WOT however the FP referencing corrects the injectors so my AFR was still perfect even with the major drop of Fuel Pressure.

[Srtboost4u]

So a customer brought a zl1 pump to install in a 2010 camaro auto with a hellion twin turbo kit. We also installed id1050x injectors. Fist start up was terrible. Lots of cranking and no fuel pressure. When it finally started fuel pressure was in the 40psi range and with light throttle would drop to 10 psi. Reset the dtc's and the pressure jumped to 58-59 at idle but free revving crashes the pressure back into the 20's.

Just found this thread.... wasn't aware that we could tune the fpcm. I'll do some logging tomorrow now that I know we can lol. But does this sound mechanical or is the fpcm cal to blame?

[10_SS]

So a customer brought a zl1 pump to install in a 2010 camaro auto with a hellion twin turbo kit. We also installed id1050x injectors. Fist start up was terrible. Lots of cranking and no fuel pressure. When it finally started fuel pressure was in the 40psi range and with light throttle would drop to 10 psi. Reset the dtc's and the pressure jumped to 58-59 at idle but free revving crashes the pressure back into the 20's.

Just found this thread.... wasn't aware that we could tune the fpcm. I'll do some logging tomorrow now that I know we can lol. But does this sound mechanical or is the fpcm cal to blame?

almost sounds like its going back limp mode free revving...any dtcs free revving?

What is Requested Fue Pressure during all of this?

[Srtboost4u]

I'll log some of the pids I learned about reading this thread in the morning 10_ss. Yes it was throwing a code after free revving for the pressure sensor I believe. Once the code is set the idle pressure would drop to 40 until I reset the dtc's.

Idk what would throw it in limp mode. Used the Id data... my first time using these and I'm impressed so far. Let it idle for a few min while I was scratching my head and whether the fp was 40 or 58 the trims stayed steady and only built .8 ltft's. I tuned this car a few weeks ago with zr1 injectors and a stock pump. Fuel pressure was dropping to 43 psi and lost control of the injectors at 4600rpm. It held an 11.6 to redline but idc was 122% lol. No problems before this pump install.

So dropping a zl1 pump in wouldn't cause this issue with the stock fpcm settings?

[10_SS]

Someone that dropped a ZL1 pump in would need to answer that one. There are max pressure tables in there and the ECU, maybe you need to raise both. You can also log the Fuel Pressure Trims maybe see if they go way out when it drops to 20psi. I think the ZL1 pump is what, 65psi regulated? But the 43psi was probably being requested like mine was. I also removed the BAP just to test and I think I got down to 25psi or something due to the SS pump, it dropped like a rock when it maxed out too, not like the gradual drop from the FSCM settings. but ARF still rock solid as well.. thats great piece of mind that I know the pressure sender feedback system works as good as it does.


I also think I will push my injectors to 100% or even 105% reported DC before considering an upgrade, it appeared I had good AFR control like you did at low FP and high INJ DC.

[10_SS]

had more time to look at the Fuel Pressure settings in ECU and FCM comparing a stock ZL1 file and the stock SS file. I would think you need to copy all of the tables from the ZL1 including:

1) Fuel System: Copy whatever is in a stock ZL1 file. These is the ECU settings so any old ZL1 file should have them.

2) Fuel System/Fuel Control Module/Max Desired Pressure: Currently all set to 58psi. Increase to the ZL1 regulator pressure which is 65psi (450kpa) across the board. The stock SS trends downwards as fuel flow increases.

3) Fuel System/Fuel Control Module/Fuel Pump: Openloop DC, Openloop DC Mult, Min DC should all be copied over there are some pretty big differences.

4) There are some other settings in the FCM regarding injector flow, etc. Rumor is they are not referenced but you should update them with what is in the ECU just in case.

There is a ZL1 FCM file attached somewhere here you can copy the FCM settings from, for the ECU settings any older ZL1 file should work.

Cant guarantee they will fix the problem but I think they should. If you make these changes, report back!

[Srtboost4u]

Thanks ss. Bossman decided to try another pump assembly and they're tearing into it shortly so I'm not able to start the car. I really hope it's the pump but I will make the adjustments as soon as the new one gets here. I'll defiantly do a before and after. Were you looking at a repository file or the one that hp engineer posted?

[Srtboost4u]

Can't believe it but my problem was defiantly the fuel pump. I do see a slight drop in fuel pressure at wot but it has a bap so I don't think I'll try the zl1 settings. The id1050x's are more then enough now. 60% right at redline. Making 601hp 604ft# through the stock auto unlocked, 11 psi. 11.3 afr (ngx afx) 14• tapering up to 16 after peak torque. It's an old hellion kit with turbonetics turbos. They're defiantly in need of some attention... pissing a bit of oil. Stock bottom stock heads with ferrea valves and hardware, and a Lingenfelter cam.

Little disappointed with the power, runs done in 3rd. It's super hot and muggy. Intake temps start at 90 and end up at 106 so although the intercooler working well, still not exactly boost weather.

[10_SS]

If you enter ZL1 settings then you might b able to ditch the BAP... if its an MSD then it could fail.

[Srtboost4u]

I'm sure your right SS I'm just following orders.

[GrannySShifting]

The FPCM's injector flow rate settings have nothing to do with it running rich after a reflash. It's an injector offset. Pressure is sky high because it's in hot fuel mode.

can you eliminate this? should there be a five minute drive time before making a dyno pull with those things?

[GrannySShifting]

Without the BAP, in theory, the modified FPCM will maintain 58psi by means of pump voltage by overriding the alternator duty cycle (or whatever chops it to the fuel system). There's a table for that voltage that we had access to before the beta. Jannety says you can't go any higher than 14.5V in that table so basically, you should see flow gains from 2 things: 1) maxing out the allowable voltage at 14.5 and 2) preventing the DC from decaying with increasing RPM as it was doing stock. I don't know what % gain this is but it's not trivial. This is definitely viable as a BAP replacement if all you need is 50HP more for example.

What table is this for inceasing voltage, and are you increasing alt output voltage or voltage FPCM is sending to pump?

[GrannySShifting]

you can watch Pump DC yes right now in scanner. Current, no.

Yes on a stock return less fuel system like my 2010 Camaro you should be able to lower the fuel pressure to 30psi and hold steady at lower flow rates to make your big injectors work better since it's PWM.. On the stock SS FPSM the tuning turns down the fuel pressure at higher fuel flow rates (higher flow rates than the stock SS reaches), unsure why but they do.

Everyone would upgrade to the ZL1 FPSM module or whatever to stop this from happening. So for me and the current setup, I already had the MSD BAP and was still losing FP at WOT, but they added the FPSM PIDs to scanner and then I saw the requested FP was dropping so that meant the pump was being told to slow down... $50 basically saved me $50-150 depending what I was going to do, get a ZL1 FPSM or have mine flashed by someone. Now my FP is rock solid all the way up, but it does still need the MSD BAP or FP drops fast at WOT however the FP referencing corrects the injectors so my AFR was still perfect even with the major drop of Fuel Pressure.

Your boost pump, is it wired before or after FPCM and what is the max voltage you are running? The one we tried after the FPCM turned all the way up to 17v (Kenne Bell) throws some codes and Ive had it cut all fuel pressure in middle of 2 pulls. Ive since turned it down a hair, to the point where FP started dropping (its set to 60 psi across board now and was holding that on dyno) then turned it back up a little bit so it held pressure again. Guessing we are 15.8-16.5 volts now

[10_SS]

Your boost pump, is it wired before or after FPCM and what is the max voltage you are running? The one we tried after the FPCM turned all the way up to 17v (Kenne Bell) throws some codes and Ive had it cut all fuel pressure in middle of 2 pulls. Ive since turned it down a hair, to the point where FP started dropping (its set to 60 psi across board now and was holding that on dyno) then turned it back up a little bit so it held pressure again. Guessing we are 15.8-16.5 volts now

It's wired after the FSCM so the FSCM doesnt know it's there. I've never loaded the MSD software to read it, I guess I'll have to see if I can pull the current setup, been curious about that. I'll see if I can do it and post the settings.