High Fuel Pressure - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

cptslow · 05-11-2018, 08:11 PM

Hi all. Questions about cruzing/idle fuel pressure.

I upgraded to the zl1 pump and ADM controller at the time I supercharged the car. I let my tuner know about these upgrades and gave him the fpcm data from ADM. I've had drivability problems intermittently, and it seems to be caused by high fuel pressure at cruise and idle. It is always at 65 and will sometimes creep up to 70 when coasting to a stop. It usually floods and dies then.

Tuner doesn't know why the pressure is so high and he has not gotten any response from his contact at HP tuners. Any idea what we've missed in the tune? Any and all suggestions are welcome.

Cheers!

43Camaro · 05-11-2018, 08:52 PM

That combination is being used and has been used by hundreds if not thousands of tuners. What size injectors are u running? What supercharger kit did you install? Sounds like you may want to find another tuner, this sounds like a tune issue or lack of experience by the tuner. Opinion is without knowing everything you are running..

cptslow · 05-11-2018, 08:57 PM

Quote:

Originally Posted by 43Camaro

That combination is being used and has been used by hundreds if not thousands of tuners. What size injectors are u running? What supercharger kit did you install? Sounds like you may want to find another tuner, this sounds like a tune issue or lack of experience by the tuner. Opinion is without knowing everything you are running..

Eforce, 1050x, 2.75" pulley, alky, lsx376-b15. There are a lot of changes in the tune to accommodate this setup. His tuning is solid - this is the 5th car I've had him do, but I'm sure we've just missed something (hopefully simple).

43Camaro · 05-11-2018, 09:06 PM

Your setup is similar To mine other than the fact I run a smaller pulley and FIC 1000 Injectors. What injectors are you running?

cptslow · 05-11-2018, 09:17 PM

Quote:

Originally Posted by 43Camaro

What injectors are you running?

ID1050x

cptslow · 05-13-2018, 06:55 PM

No suggestions from anyone? I was hoping this was something one of you had seen before...

TWOFORTYZ · 05-13-2018, 09:41 PM

A 5psi gain in pressure will NOT cause your car to stall from being too rich. I've had vehicles running 10psi over and under factory spec without tuning without stalling issues.

If you want to find out why your pressure is unstable I would check your fuel pressure regulator. A restricted return line also has potential to increase fuel pressure.

My guess is atleast one of the tuning parameters is incorrect. It happens to everyone at some point.

cptslow · 05-13-2018, 11:55 PM

Quote:

Originally Posted by TWOFORTYZ

A 5psi gain in pressure will NOT cause your car to stall from being too rich.

I agree, but since cruising pressure should be 48-50 psi, I'm actually 15-20 over.

Quote:

Originally Posted by TWOFORTYZ

If you want to find out why your pressure is unstable I would check your fuel pressure regulator. A restricted return line also has potential to increase fuel pressure.

It's a factory zl1 pump that is returnless. No regulator or return line. The variable pump is commanded by the ECM. Pressure is read in the line just past the tank.

I agree that it is just a tuning parameter that's been missed. That's why I'm reaching out for suggestions of where in the tune we've missed something.

craigd853 · 05-14-2018, 07:56 AM

Quote:

Originally Posted by cptslow

I agree, but since cruising pressure should be 48-50 psi, I'm actually 15-20 over.

It's a factory zl1 pump that is returnless. No regulator or return line. The variable pump is commanded by the ECM. Pressure is read in the line just past the tank.

I agree that it is just a tuning parameter that's been missed. That's why I'm reaching out for suggestions of where in the tune we've missed something.

There is a control module for the fuel pump that Ted Jannety sells when putting in a ZL1 fuel pump. It is pre-programmed for this pump Maybe this is what is causing your high fuel pressure readings. Hope this helps

cptslow · 05-14-2018, 09:03 PM

Quote:

Originally Posted by craigd853

There is a control module for the fuel pump that Ted Jannety sells when putting in a ZL1 fuel pump. It is pre-programmed for this pump Maybe this is what is causing your high fuel pressure readings. Hope this helps

I'm using the zl1 fpcm from ADM. It came pre programmed.

JANNETTYRACING · 05-15-2018, 08:23 AM

Quote:

Originally Posted by cptslow

Hi all. Questions about cruzing/idle fuel pressure.

I upgraded to the zl1 pump and ADM controller at the time I supercharged the car. I let my tuner know about these upgrades and gave him the fpcm data from ADM. I've had drivability problems intermittently, and it seems to be caused by high fuel pressure at cruise and idle. It is always at 65 and will sometimes creep up to 70 when coasting to a stop. It usually floods and dies then.

Tuner doesn't know why the pressure is so high and he has not gotten any response from his contact at HP tuners. Any idea what we've missed in the tune? Any and all suggestions are welcome.

Cheers!

The fuel pressure you are reporting is normal.

I suspect the problem is in the injector data entered in the tune.

If the injector data is not correct the computer does not know what pulse width to run when the pressure changes.

Ted.

Juiced1 · 05-15-2018, 08:56 AM

Quote:

Originally Posted by cptslow

Hi all. Questions about cruzing/idle fuel pressure.

I upgraded to the zl1 pump and ADM controller at the time I supercharged the car. I let my tuner know about these upgrades and gave him the fpcm data from ADM. I've had drivability problems intermittently, and it seems to be caused by high fuel pressure at cruise and idle. It is always at 65 and will sometimes creep up to 70 when coasting to a stop. It usually floods and dies then.

Tuner doesn't know why the pressure is so high and he has not gotten any response from his contact at HP tuners. Any idea what we've missed in the tune? Any and all suggestions are welcome.

Cheers!

You'll need to data log the problem and bring it to your tuner. I'm guessing something is causing your fuel trims to spike and dump fuel.

cptslow · 05-15-2018, 07:15 PM

Quote:

Originally Posted by JANNETTYRACING

The fuel pressure you are reporting is normal.

I suspect the problem is in the injector data entered in the tune.

If the injector data is not correct the computer does not know what pulse width to run when the pressure changes.

Ted.

Ok. Thanks Ted. I never logged stuff before all of these upgrades, so I figured I was running too high. I'm old school enough that I expected idle/cruise to be around 48# and then the boost reference would push the pressure up to 65#.

cptslow · 05-15-2018, 07:21 PM

Quote:

Originally Posted by Juiced1

You'll need to data log the problem and bring it to your tuner. I'm guessing something is causing your fuel trims to spike and dump fuel.

Thanks juiced. I'll keep working with my tuner and logging the problems. It is only intermittent and seems to be related to DFCO. We see fuel get cut for the first bit when coasting to a stop, and then it quits when the pressure spikes to 70# and runs rich as a pig.

Anything I'm missing in my DFCO settings?

The upgrade to ID1050x is recent too, but we double checked that data to be sure it's not off...

05-11-2018, 08:11 PM	#1
cptslow Drives: 2014 2SS/RS L99 Join Date: May 2015 Location: Southeast Idaho Posts: 26	High Fuel Pressure Hi all. Questions about cruzing/idle fuel pressure. I upgraded to the zl1 pump and ADM controller at the time I supercharged the car. I let my tuner know about these upgrades and gave him the fpcm data from ADM. I've had drivability problems intermittently, and it seems to be caused by high fuel pressure at cruise and idle. It is always at 65 and will sometimes creep up to 70 when coasting to a stop. It usually floods and dies then. Tuner doesn't know why the pressure is so high and he has not gotten any response from his contact at HP tuners. Any idea what we've missed in the tune? Any and all suggestions are welcome. Cheers!

05-11-2018, 08:52 PM	#2
43Camaro Drives: [COTW 8/3/15] 2010 Camaro SS L99 Join Date: Mar 2015 Location: Mooresville NC Posts: 434 View My Garage	That combination is being used and has been used by hundreds if not thousands of tuners. What size injectors are u running? What supercharger kit did you install? Sounds like you may want to find another tuner, this sounds like a tune issue or lack of experience by the tuner. Opinion is without knowing everything you are running.. __________________ A Little bit of power. ALL WORK DONE BY ME! Just added 2021 ZL1 1LE to the Stable! https://www.camaro5.com/forums/showthread.php?t=418273

05-11-2018, 09:06 PM	#4
43Camaro Drives: [COTW 8/3/15] 2010 Camaro SS L99 Join Date: Mar 2015 Location: Mooresville NC Posts: 434 View My Garage	Your setup is similar To mine other than the fact I run a smaller pulley and FIC 1000 Injectors. What injectors are you running? __________________ A Little bit of power. ALL WORK DONE BY ME! Just added 2021 ZL1 1LE to the Stable! https://www.camaro5.com/forums/showthread.php?t=418273

05-13-2018, 09:41 PM	#7
TWOFORTYZ Drives: 2015 Camaro 1SS 6M Join Date: Dec 2017 Location: The Freeway Posts: 238	A 5psi gain in pressure will NOT cause your car to stall from being too rich. I've had vehicles running 10psi over and under factory spec without tuning without stalling issues. If you want to find out why your pressure is unstable I would check your fuel pressure regulator. A restricted return line also has potential to increase fuel pressure. My guess is atleast one of the tuning parameters is incorrect. It happens to everyone at some point. __________________

05-13-2018, 06:55 PM	#6
cptslow Drives: 2014 2SS/RS L99 Join Date: May 2015 Location: Southeast Idaho Posts: 26	No suggestions from anyone? I was hoping this was something one of you had seen before...