20 captured repliesPartial discussion capture · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHCar cranks but doesn't start - Part 2 - 986 Forum - The Community for Porsche Boxster & Cayman Owners
Leading reported evidence
Install today, replacing the bosch h8
Performed · outcome unconfirmed
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 performed work without a confirmed outcome
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.
Performed · outcome unconfirmed · Original poster
A new ACDelco H7 AGM battery was delivered and installed today, replacing the Bosch H8.
Car cranks but doesn't start - Part 2 - 986 Forum - The Community for Porsche Boxster & Cayman Owners
Read full discussion summary
Leading evidence: 'Install today, replacing the bosch h8' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'issue' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Check battery' (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 performed work without a confirmed outcome
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.
Performed · outcome unconfirmed · Original poster
Rather than staying true to, "Don't fix what's not broken", I changed the battery to ACDelco and the car idled rough.
Car cranks but doesn't start - Part 2 - 986 Forum - The Community for Porsche Boxster & Cayman Owners
issue
Suggestion or failed attempt
No successful repair reported for this finding.
0
Identified cause
1
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 suspect 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.
Suspected cause
Since your tach doesn't move at all, this is most likely the issue, but I would do the below as it takes less then a half hour to do also.
Car cranks but doesn't start - Part 2 - 986 Forum - The Community for Porsche Boxster & Cayman Owners
Check battery
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.
Suggestion
I wouldnt rely on the tool telling you charging volt, I would check the battery with volt meter while the car is running.
Car cranks but doesn't start - Part 2 - 986 Forum - The Community for Porsche Boxster & Cayman Owners
Check codes
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.
Suggestion · Original poster
I have been checking for the codes with Durametric and generic code reader since the car-start-problem first showed up a month ago.
Car cranks but doesn't start - Part 2 - 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.
20 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: 20261027T000231Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
You can find Part 1 to this saga here...
http://986forum.com/forums/boxster-general-discussions/81201-car-cranks-but-doesnt-start.html
A new ACDelco H7 AGM battery was delivered and installed today, replacing the Bosch H8. For the past 5 days, since the replacement of AOS, the car had no trouble starting.
Rather than staying true to, "Don't fix what's not broken", I changed the battery to ACDelco and the car idled rough. I understand this is expected when you disconnect battery so I wasn't worried.
I was careful to watch the charging voltage via this tool I have. It was 14.30ish volts.
Anyway, about 5~10 mins into idling, car died. And I can't start the car anymore.
Why would a car die while idling?
A blocked fuel filter?
Bad plugs? Did the AOS failing contaminated the plugs?
What do you guys think?
Thanks in advance.
Try re-calibrating the E-gas pedal.
Turn key to the on position for 1 minute.
Do not try to start the car. do not touch the gas pedal.
Turn key off for at least 10 seconds.
Then see if the car will start.
changing the battery wont cause it to run rough.
Need more info. car wont start isn't enough.
does it crank over?
does the tach move?
did you check for codes? If so are there any?
I wouldnt rely on the tool telling you charging volt, I would check the battery with volt meter while the car is running. 10 minutes isn't enough to drain the battery down so there is still something else going on with the car besides the battery.
think I know what the issue is, but want to see answers to the above first. I'll have some steps for you to perform depending on answer. I dont think your battery has anything to with this issue or the one in your other post. Doesn't seem sound like your intermittent no start was resolved from then.
Hi blue62,
Does this, "Turn key to the on position for 1 minute" means to turn it turn so that you get the oil level reading? I did that. And then tried to start the car for 10+ seconds. Nothing.
BTW, I am going to take the new battery out and replace it with what I had yesterday.
This battery gave me no trouble until yesterday. It is currently being charged.
Hi Stl-986,
It cranks. It always did.
The tach does not move.
I have a generic code reader and nothing shows there. I am wondering if Durametric will show more. (But then, I don't know what I am looking for in it...
) )
First, do a search for CPS/crank position troubleshooting. If that testing is successful, do the following. Since your tach doesn't move at all, this is most likely the issue, but I would do the below as it takes less then a half hour to do also.
, do the following
put top in service position
remove engine cover carpet & engine cover
DO THE NEXT WITH ENGINE COLD!!!!
Remove fuel cap
Wait 1 minute, then put back on
Go to pass side of engine. Using a small screwdriver, press the schrader valve on the fuel line. Does fuel come out? Valve may have a cover on it, if so, remove.
If no fuel, turn key to ON position
Do above again, any fuel come out?
If no, remove fuel pump relay (gray with pink wriring)
make a jumper wire
Jumper fuel pump
turn key to on, dont start car
Go press schrader valve at fuel rail.
Any fuel come out?
If the last answer is No, then you need a new fuel pump.
Some would say to jumper the fuel rail, turn key to on and listen for pump (it's under the battery). But depending on how much gas is in the tank you might not hear it run. I know I didn't with 3/4 full tank 2 weeks ago.
Wow... I need to research where the "schrader valve on the fuel line" is. Perhaps I will upload a picture of my engine bay and you can circle it for me.
Thank you Stl-986.
P. S. So.... you don't think it is dirty plugs, right? I was SO hoping it would be 11 year old plus plugs...
The valve is on the front (forward) end of the bank 1 (passenger side) fuel rail.
Be careful while doing this, the test is to see if the fuel pump is pressurizing the fuel rails. If it does, then you will have fuel spray out and into your engine bay (this is why he told you to do it with a cold engine).
Have a fire extinguisher ready.
Sent from my SM-G970U1 using Tapatalk
"Have a fire extinguisher ready. "
OMG!!!
I don't even have one for my house! (I did think about buying one for the car. I am not crazy, right? That's normal Boxster love, right?
)
Thanks ike84!
OK, here is the update. The car starts!
While researching the "CPS/crank position troubleshooting"... I came across this gentleman, Brian Minson.
https://youtu.be/ZSmehtE8Ctk
At 14:00 mark, he explains how to check the CPS.
It is just what YOU asked me earlier, "does the tach move?" I say no, but the amount of 'movement' is way smaller than I was expecting. I will look for this tiny tach movement, or not, the next time when the car won't start. In fact, it was to confirm this tiny tach movement when the car magically started. Brian's description of CPS failed car is 95% dead on with my experience.
Questions:
- is failing CPS sensitive to temperature? Ambient temperature? Or, engine temperature?
- Could a bad CPS stop the engine while driving?
As always, thank you for your help.
heat can cause the cps to have issues
no it wont stop the engine from running
The fact that your tach moves means that the issue isn't the cps
You have a failing fuel pump. everything you describe is exactly what happens when it starts to fail. I know, just went through this 2 weeks ago. Sometimes it will work, some times it wont.
So that everyone doesn't have to ask every time, put your car info in your signature. 99 & earlier use 1 type of pump, 2000 & above use a different one. Replace it before it strands you somewhere. You haven't said if you checked for codes at any time and if any where shown. If you did before it started and there were no codes....then it is fuel pump.
If your tach moves....it isn't CPS
You should always have an extinguisher in the house and one in the car....regardless of what kind of car you have. Hell, I have 3 in the garage and 2 in the house. Better to have and not need then need and not have. Cheaper too.
I am not sure if tach moved when my car wouldn’t start. Yes, if the tach jumps a bit without car starting, I now know that I can eliminate CPS. I just don’t have this data point, yet.
If the problem is the failing fuel pump, shouldn't I have had some symptoms while I was driving?
I have been checking for the codes with Durametric and generic code reader since the car-start-problem first showed up a month ago. No codes. Not then. Not now.
