HPFP Replacement
02-12-2021, 04:40 AM
#1
HPFP Replacement
Hello folks,
This is my first post here, and I'm also a forest time Porsche owner. I got a 2010 Cayman S manual and have been loving the car. Recently it's been having very long crank times if it sits for more than an hour and also sputters on first start (no codes yet). Anyways, in researching I think it's a dying HPFP. It's quite expensive to repair so I'd like to do it myself, if possible. Has anyone changed one of these? The best DIY write-up I could find was for a 997.2 on this forum. I've tried buying some emanuals online but they don't have good info. Any help would be appreciated. Thanks.
This is my first post here, and I'm also a forest time Porsche owner. I got a 2010 Cayman S manual and have been loving the car. Recently it's been having very long crank times if it sits for more than an hour and also sputters on first start (no codes yet). Anyways, in researching I think it's a dying HPFP. It's quite expensive to repair so I'd like to do it myself, if possible. Has anyone changed one of these? The best DIY write-up I could find was for a 997.2 on this forum. I've tried buying some emanuals online but they don't have good info. Any help would be appreciated. Thanks.
02-12-2021, 01:18 PM
#2
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I also did it on my 997.2 S, it wasn't that bad but I also had the exhaust off. I am sure the mid-engine is a different animal and complicates the removal potentially. Or maybe easier?? I remember it wasn't that difficult once I had access.
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zzyx (02-20-2021)
02-12-2021, 04:45 PM
#3
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Before spending the large $$ to replace the HPFP on a guess - I'd suggest taking two steps:
1. Buy a diagnostics tool that can give you data on the fuel pump. There is electronic monitoring of it's input/output pressures. It's entirely possible it is the HPFP, but it's also possible that it's the low-pressure tank pump that feeds the high-pressure pump or - a fuel filter (usually part of the pump fitting on the tank.) You have 2 ways of determining this - spend a lot of money and effort replacing the pumps - or diagnosing the problem first and knowing where the issue is.
2. Join AllDataDIY.com - much better than any on-line manuals, and better than downloadable manuals. Targeted at your year/model of Porsche - it should have diagnostics on the fuel system that will give you a hint what you're looking for.
Welcome to the forum!
1. Buy a diagnostics tool that can give you data on the fuel pump. There is electronic monitoring of it's input/output pressures. It's entirely possible it is the HPFP, but it's also possible that it's the low-pressure tank pump that feeds the high-pressure pump or - a fuel filter (usually part of the pump fitting on the tank.) You have 2 ways of determining this - spend a lot of money and effort replacing the pumps - or diagnosing the problem first and knowing where the issue is.
2. Join AllDataDIY.com - much better than any on-line manuals, and better than downloadable manuals. Targeted at your year/model of Porsche - it should have diagnostics on the fuel system that will give you a hint what you're looking for.
Welcome to the forum!
02-23-2021, 04:43 AM
#4
Hi. Thanks for the advice. I got a Durametric and logged high pressure setpoint and actual during startup. It looks like after cranking, the initial pressure is only at 10bar for about 10sec when the engine is running rough, then builds to match the setpoint of 50bar and runs smooth after that. If I rev up to 2k RPM immediately after startup, there's no right idle.
During driving, the pressure seems to track the setpoint well from 40bar to 100bar at WOT and the engine never skips a beat. It pulls well all the way to redline and has good transient throttle response at all RPMs.
Any thoughts on what could cause the bad startup? I've tried doing multiple key on/key off cycles before cranking to try to prime the low pressure fuel circuit but that doesn't help.
During driving, the pressure seems to track the setpoint well from 40bar to 100bar at WOT and the engine never skips a beat. It pulls well all the way to redline and has good transient throttle response at all RPMs.
Any thoughts on what could cause the bad startup? I've tried doing multiple key on/key off cycles before cranking to try to prime the low pressure fuel circuit but that doesn't help.