Questions about the HPFP

chavomilkstain · 03-14-2023, 09:40 PM

Went to start the car yesterday, did not fire off. Pulled the codes, had a P00C6 (low rail pressure, cranking) set. Verified my rail pressure was indeed around 80psi, much lower than requested. Tore topside down, removed HPFP to ensure all was good there. Everything seems to be in order, no leaks, no broken bolts or fuel lines, cam follower present and not binding. This is post cam install, so there is a lash cap present on the cam follower. Lash cap still present and seated, not stuck in the spring. How do I know if the pump is bad? I did also load every tune I had saved (stock, basemap after cam, idle tunes, etc), did not fix, so I'm assuming it's nothing tune related.

chavomilkstain · 03-14-2023, 09:41 PM

I have pictures of the pump and down inside the pump housing, as well as my tune files present and some logs if anyone has the time to sit down and sift through that.

CW3SF · 03-14-2023, 09:48 PM

Maybe one of the experts chime in here but I when I replaced my HPFP with an aftermarket one I did not encounter a lash cap, but I’m on stock cam. I’ve read that the LT1 uses one but not the LT4. Maybe someone more mechanically inclined can clarify.

chavomilkstain · 03-14-2023, 09:51 PM

Quote:

Originally Posted by CW3SF

Maybe one of the experts chime in here but I when I replaced my HPFP with an aftermarket one I did not encounter a lash cap, but I’m on stock cam. I’ve read that the LT1 uses one but not the LT4. Maybe someone more mechanically inclined can clarify.

There are several posts in here from a few years ago about the lash cap/no lash cap/failed pump thing, but I didn't want to revive long dead threads. Do you off the top of your head know of any ways to verify if the pump mechanically failed or not? I only have that P00C6 code.

chavomilkstain · 03-14-2023, 10:21 PM

Looking back through the last log, the desired fuel rail pressure is maxed at 2900. Is that normal for a start?

GXP08jrf · 03-15-2023, 08:32 AM

Try internet searching for TSB #PIP5130K, which sounds like your symptoms.

Generally it's related to a camshaft position actuator solenoid valve sticking/binding.

chavomilkstain · 03-15-2023, 01:07 PM

Quote:

Originally Posted by GXP08jrf

Try internet searching for TSB #PIP5130K, which sounds like your symptoms.

Generally it's related to a camshaft position actuator solenoid valve sticking/binding.

I'll give this a whirl. It has been cold here and I have break in oil still flowing, so that maybe could have binded it up. Appreciate the assistance!

chavomilkstain · 03-15-2023, 06:03 PM

Quote:

Originally Posted by GXP08jrf

Try internet searching for TSB #PIP5130K, which sounds like your symptoms.

Generally it's related to a camshaft position actuator solenoid valve sticking/binding.

Would this work even though I have a phaser lockout installed? 0° plug is installed, so phaser isn't moving. I feel I'm answering my own question at this point. Lol. Sucks that HPFPs are in a nationwide shortage.

Chrome383Z · 03-15-2023, 09:24 PM

Yeah even the passenger side wire harness is in a shortage. I have one on order chasing a fuel pump problem. Taking forever. blah

chavomilkstain · 04-09-2023, 05:27 AM

Update: bit the bullet and ordered the LPE high pressure pump, installed, still no start. Pump pressure fault went away, which is an improvement. Hoping it's just plugs at this point and not what one guy in here dealt with in a sheared off cam dowel pin. Fingers crossed, boys and girls!

2023_ZL1-AUTO · 08-11-2023, 09:58 AM

chavomilkstain - Did you get this resolved? I assume you did, could you share the resolution?

Thanks

03-14-2023, 09:40 PM	#1
chavomilkstain Drives: 2022 Black ZL1 M6 Join Date: Nov 2021 Location: Alaska Posts: 19	Questions about the HPFP Went to start the car yesterday, did not fire off. Pulled the codes, had a P00C6 (low rail pressure, cranking) set. Verified my rail pressure was indeed around 80psi, much lower than requested. Tore topside down, removed HPFP to ensure all was good there. Everything seems to be in order, no leaks, no broken bolts or fuel lines, cam follower present and not binding. This is post cam install, so there is a lash cap present on the cam follower. Lash cap still present and seated, not stuck in the spring. How do I know if the pump is bad? I did also load every tune I had saved (stock, basemap after cam, idle tunes, etc), did not fix, so I'm assuming it's nothing tune related.

03-15-2023, 09:24 PM	#9
Chrome383Z Drives: 2019 Camaro 2SS Join Date: Aug 2020 Location: McCordsville, Indiana Posts: 622	Yeah even the passenger side wire harness is in a shortage. I have one on order chasing a fuel pump problem. Taking forever. blah __________________ 2019 Shock 2SS A10. 2650@10psi/LPE HPFP/XDI+30/LT4 LPFP+JMS/Soler 95mm/Rotofab, E65, CSP 2” Headers/GESI GenII Cats. MM Wild/GM SG3 suspension/1LE Brakes, Velgen VF5 Wheels/GY SC3. JRE Tuned.

08-11-2023, 09:58 AM	#11
2023_ZL1-AUTO Drives: 2023 ZL1 Join Date: Dec 2022 Location: Columbus, Ohio Posts: 1,287	chavomilkstain - Did you get this resolved? I assume you did, could you share the resolution? Thanks __________________ Katech Track Day CAM 38%•BTR Dual Valve Springs•Johnson Lifters•Trend 3/8 Chromoly Pushrods• VVT Del•CNC Heads•AFM Delete• C5-R Timing Chain•Katech Oil Pump•Katech 112mm•Maggie 2650 3.25” Upper/ATI SD w/10.32” +20%•10 Rib Belt•RFBG•FI IC Stage 2•THPSI Port w/875cc Inj•Katech Dual Fuel Pump•DSX Aux Pump•SW 2" Headers w/Legend NPP•GESI UHO 4.5" CATs•Brisk RR14S Plugs•BMR Motor Mounts•BMR Cradle Lockout &Bushings Kit•BMR Rear Suspension & 15" Conversion•DSS 1pc DS•RPM 6-Point Roll Cage•10lb FireSense+ w/4Fire SFI 17.1 Fire Sys•Weld Forged Vitesse Rear 17x10 Beadlocks-Front 18x6•Unlocked TCM

03-14-2023, 09:41 PM	#2
chavomilkstain Drives: 2022 Black ZL1 M6 Join Date: Nov 2021 Location: Alaska Posts: 19	I have pictures of the pump and down inside the pump housing, as well as my tune files present and some logs if anyone has the time to sit down and sift through that.

03-14-2023, 09:48 PM	#3
CW3SF Drives: 2019 Chevy Camaro ZL1 M6 Join Date: Jul 2019 Location: Sea level Posts: 1,276 View My Garage	Maybe one of the experts chime in here but I when I replaced my HPFP with an aftermarket one I did not encounter a lash cap, but I’m on stock cam. I’ve read that the LT1 uses one but not the LT4. Maybe someone more mechanically inclined can clarify.

03-14-2023, 10:21 PM	#5
chavomilkstain Drives: 2022 Black ZL1 M6 Join Date: Nov 2021 Location: Alaska Posts: 19	Looking back through the last log, the desired fuel rail pressure is maxed at 2900. Is that normal for a start?

03-15-2023, 08:32 AM	#6
GXP08jrf Drives: 2016 1LT 'Vert Join Date: Feb 2022 Location: Midwest Posts: 184	Try internet searching for TSB #PIP5130K, which sounds like your symptoms. Generally it's related to a camshaft position actuator solenoid valve sticking/binding.

04-09-2023, 05:27 AM	#10
chavomilkstain Drives: 2022 Black ZL1 M6 Join Date: Nov 2021 Location: Alaska Posts: 19	Update: bit the bullet and ordered the LPE high pressure pump, installed, still no start. Pump pressure fault went away, which is an improvement. Hoping it's just plugs at this point and not what one guy in here dealt with in a sheared off cam dowel pin. Fingers crossed, boys and girls!

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