[carbon fibr]

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.
I can provide the log if anyone's interested in giving me a second opinion

[Joshinator99]

Originally Posted by carbon fibr

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.
I can provide the log if anyone's interested in giving me a second opinion

If your low side drops off, it will then let the high side drop off. When the HPFP cannot keep up, it loses it big time! The rail pressure will simply fall off a cliff…. What was your low side holding at? What did your IPW look like? E55 seems like a lot for a stock fuel system LT4.

[Z OH 6]

Originally Posted by Joshinator99

If your low side drops off, it will then let the high side drop off. When the HPFP cannot keep up, it loses it big time! The rail pressure will simply fall off a cliff…. What was your low side holding at? What did your IPW look like? E55 seems like a lot for a stock fuel system LT4.

That's what I was thinking too. I think he's trying to run too much ethanol and the fuel system can't keep up.

[carbon fibr]

Originally Posted by Joshinator99

If your low side drops off, it will then let the high side drop off. When the HPFP cannot keep up, it loses it big time! The rail pressure will simply fall off a cliff…. What was your low side holding at? What did your IPW look like? E55 seems like a lot for a stock fuel system LT4.

At WOT, low side pressure = 62 to 70psi.
IPW average bank 1 & 2 = 5.3ms

Ya I understand its too much E, I wanted to find that limit. But 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. The HPFP is broken I guess?

[2023_ZL1-AUTO]

Have you considered adding a JMS fuel pump booster or Aux Pump for the low side? When I had my stock setup with 2" headers, stock blower, stock pulleys and misc. other mods, I was only able to get to E60, but it required the JMS Fuel Booster. That or install an Aux pump system. The JMS seemed to be to be a lot less "F'n" with the car as you don't need to drill the tank etc. etc. ? Also, did your tuner give you an E mix that they said was ok/safe to run?

[carbon fibr]

Originally Posted by 2023_ZL1-AUTO

Have you considered adding a JMS fuel pump booster or Aux Pump for the low side? When I had my stock setup with 2" headers, stock blower, stock pulleys and misc. other mods, I was only able to get to E60, but it required the JMS Fuel Booster. That or install an Aux pump system. The JMS seemed to be to be a lot less "F'n" with the car as you don't need to drill the tank etc. etc. ? Also, did your tuner give you an E mix that they said was ok/safe to run?

yup, I actually just ordered one, along with the $900 new HPFP I had to buy. Id still be having issues with destroying my HPFP though I believe.

[2023_ZL1-AUTO]

So... this was my fuel pressure with no E mix during a pull in Mexico! (see photo)

Also, below is the link to my complete build log and specifically post #215 is where I install my JMS Fuel Booster! Good luck!

https://www.camaro6.com/forums/showthread.php?t=611982

[Joshinator99]

Sent your logs to Megahurtz or KingLT1 and let them have a look.

[2018ZL1]

Scratching my head on the high side pump taking a shit... I would have thought something much worse would have happened if the high side leaned out! I wouldnt think it running out of fuel would have damaged it? I could be wrong though!

[KingLT1]

It's just coincidental...the ethanol didn't make your pump crap out. Not sure how your tuner could have screwed up your pump either unless he was for some reason commanding more rail pressure than what the LT4 can tolerate.