7 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHCranks but won't fire - 986 Forum - The Community for Porsche Boxster & Cayman Owners
Reported or suspected cause
stuck fuel pressure relay
Reported cause
No successful repair reported for this finding.
1
Identified cause
0
Suspected cause
0
Reported fixes
Read evidence and context
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.
Discussions that report identifying a cause
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Reported cause
My problem turned out to be a stuck fuel pressure relay.
Cranks but won't fire - 986 Forum - The Community for Porsche Boxster & Cayman Owners
Read full discussion summary
Leading evidence: 'stuck fuel pressure relay' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'stuck fuel pressure relay' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Check fuel pressure' (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.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
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.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Cranks but won't fire - 986 Forum - The Community for Porsche Boxster & Cayman Owners
Check fuel pump
Suggestion or failed attempt
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Cranks but won't fire - 986 Forum - The Community for Porsche Boxster & Cayman Owners
Check fuse first
Suggestion or failed attempt
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Cranks but won't fire - 986 Forum - The Community for Porsche Boxster & Cayman Owners
Coverage and how to read this overview
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
7 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
986Forum: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
0 acknowledgements have no verified action link; they do not establish a repair result.
Generation: 20261026T074343Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
Jumped in the car this morning & it cranks fine but won't fire.
It's obviously electrical but not sure what the possibilities are.
Will start with fuses & go from there.
Any assistance would be greatly appreciated.
Take off the gas (petrol?) cap and listen at the fill neck for a whirring sound when the ignition is turned on. If there is no sound, then the fuel pump is not working. Check the fuse first.
When the engine is cranking, does the tachometer show any revs? If not, then the crank position sensor is not working.
I had the same situation several months ago. Diagnose this methodically. Think spark, fuel and then air/electrical. If fuses check out and it's not the crank position sensor then start with spark. Easy to pull a coil pack and shove a grounded plug into it and crank the engine. Look for a nice blue spark.
Next pull the fuel pump relay and jumper it. It's another check to what Spinnaker said but with your head in the footwell, you should hear the pump turn on as soon as you jumper the relay. If the pump runs, you're probably getting fuel so Che k the relay for continuity and function. Energize it and see if it clicks (relays are making contact). If not, bad relay. Just because your fuel pump runs doesn't mean you are getting fuel (ask me how I know). Check fuel pressure. My problem turned out to be a stuck fuel pressure relay. Good luck...
CPS sends a tach signal. IIRC from when mine died - you should see a blip on tach if it is sending a signal. On the other hand - my original durametric worked only once and that was able to I’d the failed CPS.
Hello Spinnaker.
I'm trying to diagnose a startup problem after the car has been sitting for a while. Would the tach jumping just above zero constitute a functional crank position sensor? Thanks!
yes
CPS usually fail due to heat .. not starting after sitting depending if it is overnight or not , can either be cold start enrichment issue , or residual fuel pressure drop . depending on your particular scenario.
