Camaro ZL1, LT4. E85 tune = Broken HPFP

[pauljauch]

Hi all.
2021 Camaro ZL1, LT4 engine, Manual Trans. Mods: 2" Headers, Intake, Cat delete, DSX flex fuel Sensor.

Curious if anyone has come into issues with a failed High Pressure Fuel Pump (HPFP) after doing an E85 tune.
Got my car up to 55% Ethanol, did a few pulls and after the last pull my HPFP dropped right off to 50psi. Codes: P228C - Fuel Pressure Regulator Control Performance - Low Pressure, P0089 - Fuel Pressure Regulator Performance.
I was dialing in my last tune, verifying if my low-pressure fuel could supply up to 50-60% Ethanol. I didn't expect my HPFP to break; Curious if it could be related to my tune? I'm scared to run E85 now.
FYI: I just ordered a Fuel pump voltage booster & a new stock LT4 HPFP.

Any help greatly appreciated.
attached is the log, you can see it drop off after the last pull while I'm just cruising.
paul jauch zl1 log9.hpl

[edcmat-l1]

Did the pressure drop off because the low side couldn't keep up? Did not look at the log, just asking.

The pump did not physically break, you just got a low pressure code?

[Alvin]

Hi all.
2021 Camaro ZL1, LT4 engine, Manual Trans. Mods: 2" Headers, Intake, Cat delete, DSX flex fuel Sensor.

Curious if anyone has come into issues with a failed High Pressure Fuel Pump (HPFP) after doing an E85 tune.
Got my car up to 55% Ethanol, did a few pulls and after the last pull my HPFP dropped right off to 50psi. Codes: P228C - Fuel Pressure Regulator Control Performance - Low Pressure, P0089 - Fuel Pressure Regulator Performance.
I was dialing in my last tune, verifying if my low-pressure fuel could supply up to 50-60% Ethanol. I didn't expect my HPFP to break; Curious if it could be related to my tune? I'm scared to run E85 now.
FYI: I just ordered a Fuel pump voltage booster & a new stock LT4 HPFP.

Any help greatly appreciated.
attached is the log, you can see it drop off after the last pull while I'm just cruising.
paul jauch zl1 log9.hpl

Did fuel pressure come back when you reset the code and restarted?

[pauljauch]

Did the pressure drop off because the low side couldn't keep up? Did not look at the log, just asking.

The pump did not physically break, you just got a low pressure code?

The pump is physically broken I think, Cant get over 50psi high pressure anymore. During the run At WOT, low side pressure = 62 to 70psi.
IPW average bank 1 & 2 = 5.3ms
breaking a $1000 HPFP was not something I thought was going to happen. Could the pump be over-spun? Could I be asking too much of the pump?

High pressure fuel at WOT ranging from about 2850-2950, Then around redline it spikes to 3200psi sometimes, not all the time.

Car barely starts right now, cranks for like 20 seconds then starts and my High pressure fuel is at 50-60psi. Fault comes right back, The HPFP is broken I guess?

[pauljauch]

Did fuel pressure come back when you reset the code and restarted?

nopes

[hellbents-10]

Proper lash cap measurement and preload?

[edcmat-l1]

Proper lash cap measurement and preload?

That was going to be my next question. Larger fuel pump lobe? Shimmed pump? Anything different about it mechanically or 100% OEM setup?

[GLA45cjz]

Had this happen to my car as well not lt4 thank God but still the guys that installed my engine didnt check the lash cap needed and just threw in a .080 cap and after it failed. The hpfp seal failed and dumped raw fuel into the crankcase causing all kinds of issues. After i remeasured it only needed a .060 cap.

[TriPinTaZ]

E85 wouldn't cause such an issue. If you're cammed then you very possibly had the preload incorrect on the fuel lobe and trashed the high side pump.