3 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHFuel Pump/Pressure Woes
Leading reported evidence
Check fuses, no fault
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
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Leading evidence: 'Check fuses, no fault' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check fuses, no fault' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Performed · outcome unconfirmed · Original poster
So with a dry tank, I installed the (very lightly) used pump, then the used sending unit.
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Performed · outcome unconfirmed · Original poster
Car now has a little less than 1/2 tank of fuel (new pump was submerged completely in tank when replaced).
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
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Performed · outcome unconfirmed · Original poster
4/6 - Replaced fuel pump with OE part (ordered from Porsche dealer) after determining car has no fuel pressure and pump failed 12v application.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
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3 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Pelican Parts: 1 discussions
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I'll try to keep this as factual as I can to make potential diagnosis easier. I apologize for cross-posting, but the 996 forum seems to get more traffic than the 986 does and there is commonality of parts on the fuel system.
2004 Boxster 2.7L manual, 90xxx miles.
3/30 - Last drove car, no issues. Parked with 1/4 tank (generally refuel a Shell).
4/1 - Attempted to start car, cranks but did not fire. Tested with Durametric, crank signal reads approximate 162 RPMs during cranking (also displays on tach).
4/6 - Replaced fuel pump with OE part (ordered from Porsche dealer) after determining car has no fuel pressure and pump failed 12v application. Once new pump is installed, car immediately starts and drives normally. Start/stop car multiple times without issue. No debris in tank, no kinked lines. All connectors clicked/tightened correctly.
4/7 - Attempted to start car, cranks but did not fire. Checked fuses, no fault. No fault codes read with Durametric. Changed DME and injector relays, no change.
4/10 - Replaced ignition switch. No change.
4/12 - Replaced fuel pump with another new OE part (from Porsche dealer). Again, car starts up and drives normally without issue. Cycle ignition and works perfectly. Fuel pump is audible upon power-up every few ignition cycles (if cycled rapidly), comes on momentarily then shuts off (not stuck running). No debris in tank, no kinked lines. All connectors clicked/tightened correctly.
4/13 - Attempted to start car, cranks but did not fire. Fuel pump not audible as was roughly 12 hours prior. Car now has a little less than 1/2 tank of fuel (new pump was submerged completely in tank when replaced).
4/15 - Replaced fuel pump relay, no change.
4/17 - Tested second replacement fuel pump with direct 12v power. Pump buzzes as if motor stuck, does not push fuel out of the tank. With pump relay bypassed, power socket at tank gets continuous power, but with relay in place momentary powerup upon turning the key intermittent (as seems to be normal).
Right now the plan is to get (another) fuel pump, and also change the sending unit as well. I'm wondering what the failure rate is of the fuel pressure sensor (on top of tank and connected into EVAP system).
Now, the original fuel pump was disassembled and found to be seized. The first replacement was briefly bench tested and did not turn on (I did not perform the test so I cannot confirm this fully).
Now, is there ANY idea as to why the car will run with a new fuel pump, only to not start 12 hours after the last shutdown? I'm out of ideas on how to diagnose this. Part of me thinks there could be a grounding issue with the pump, also think that it could be a bad DME or crank sensor perhaps (though the car runs immaculately when a new pump is installed).
I haven't been able to find any other real answers on how to solve this, and I'm sure I can't keep having fuel pumps warrantied. Anyone at Pelican HQ with an idea (Wayne)?
Thanks in advance for your assistance. I'm hoping to have my Boxster back on the road soon!
You did not say if you checked the fuel pressure regulator As far as a grounding problem, I think the pump is grounded at ground point 3 on the left side around the fire wall. I doubt that's causing the problem as you would also have a lot of other devices not functioning correctly.
Problem solved! Updating this so anyone else searching can see my resolution.
I returned the second faulty fuel pump, and ordered a used pump and sending unit from DC Auto. Along with those new (used) parts, a fresh fuel pump relay, and fresh fuel, the car performs. Period.
The gas I pumped out of the tank smelled old and not nearly as strong as gasoline is supposed to smell. Even after getting it on my hands, the smell largely disappeared - kind of odd. So with a dry tank, I installed the (very lightly) used pump, then the used sending unit. All locked in, I dumped in 5 gallons of fresh 93 octane (which DID smell strong). Turned the car on, nothing. Forgot to put the new pump relay in (old one was installed), so I swapped that out. Cranked, fired, booyah.
I waited about 2.5 hours and tried again. Started. On my way to work this morning (about 11 hours after the fix was completed), the car fired right up. Refilled the tank with fresh gas, then went to work. Started right back up after sitting.
I'm so, so happy to be driving my Boxster again. I sorely missed having it on the road in the last three (almost four) weeks.
This is a source reference. Confirm exact model applicability in the original material.
