7 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHPotential open/closed loop problems in 996.1? Help me fix my car!
Leading reported evidence
Check fuses, battery tests good
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
(and yes, over last few months I've done a few ongoing repairs - oil change, oil pressure spring/piston, new fuel pump, new fuel pressure regulator, new alternator, new crank position sensor, coil packs/plugs/tubes, cleaned and checked MAF, IACV, throttle body, checked all fuses, battery tests good, checked all grounds)
Potential open/closed loop problems in 996.1? Help me fix my car!
Read full discussion summary
Leading evidence: 'Check fuses, battery tests good' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check fuses, battery tests good' (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
(and yes, over last few months I've done a few ongoing repairs - oil change, oil pressure spring/piston, new fuel pump, new fuel pressure regulator, new alternator, new crank position sensor, coil packs/plugs/tubes, cleaned and checked MAF, IACV, throttle body, checked all fuses, battery tests good, checked all grounds)
Potential open/closed loop problems in 996.1? Help me fix my car!
Check maf, iacv, throttle body
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
(and yes, over last few months I've done a few ongoing repairs - oil change, oil pressure spring/piston, new fuel pump, new fuel pressure regulator, new alternator, new crank position sensor, coil packs/plugs/tubes, cleaned and checked MAF, IACV, throttle body, checked all fuses, battery tests good, checked all grounds)
Potential open/closed loop problems in 996.1? Help me fix my car!
Disconnect battery
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
Disconnected the battery from the car - I think there's a short or something strange as I'm getting some continuity from the positive battery terminal to ground!
Potential open/closed loop problems in 996.1? Help me fix my car!
Run normally (higher idle than normal depending
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
During the first 3 minutes the cold start enrichment is enough to keep the engine running normally (higher idle than normal depending on amount of unmetered air and whether the idle control valve can compensate) despite the extra air from the intake leak.
Potential open/closed loop problems in 996.1? Help me fix my car!
Frequently discussed actions (7)
These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.
Check fuses, battery tests good
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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
(and yes, over last few months I've done a few ongoing repairs - oil change, oil pressure spring/piston, new fuel pump, new fuel pressure regulator, new alternator, new crank position sensor, coil packs/plugs/tubes, cleaned and checked MAF, IACV, throttle body, checked all fuses, battery tests good, checked all grounds)
Potential open/closed loop problems in 996.1? Help me fix my car!
Check grounds)
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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
(and yes, over last few months I've done a few ongoing repairs - oil change, oil pressure spring/piston, new fuel pump, new fuel pressure regulator, new alternator, new crank position sensor, coil packs/plugs/tubes, cleaned and checked MAF, IACV, throttle body, checked all fuses, battery tests good, checked all grounds)
Potential open/closed loop problems in 996.1? Help me fix my car!
Check maf, iacv, throttle body
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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
(and yes, over last few months I've done a few ongoing repairs - oil change, oil pressure spring/piston, new fuel pump, new fuel pressure regulator, new alternator, new crank position sensor, coil packs/plugs/tubes, cleaned and checked MAF, IACV, throttle body, checked all fuses, battery tests good, checked all grounds)
Potential open/closed loop problems in 996.1? Help me fix my car!
Disconnect battery
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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
Disconnected the battery from the car - I think there's a short or something strange as I'm getting some continuity from the positive battery terminal to ground!
Potential open/closed loop problems in 996.1? Help me fix my car!
Run normally (higher idle than normal depending
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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
During the first 3 minutes the cold start enrichment is enough to keep the engine running normally (higher idle than normal depending on amount of unmetered air and whether the idle control valve can compensate) despite the extra air from the intake leak.
Potential open/closed loop problems in 996.1? Help me fix my car!
Run so lean
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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
Once the cold start enrichment is over then it could run so lean that the lambda control is no longer able to correct for it by injecting more fuel and the engine runs as you describe.
Potential open/closed loop problems in 996.1? Help me fix my car!
Test since i had good access
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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
Thanks guys - noticed another thing - changed the starter motor today (bought this part ages ago) and did some electrical testing since I had good access to the Y cable etc.
Potential open/closed loop problems in 996.1? Help me fix my car!
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.
Rennlist: 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: 20261026T130754Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
So I'm still working towards fixing issues in my car.... what happens is, from a dead cold start, the car starts perfectly, idles up around 1000rpm. After 3 to 3:30 minutes, it starts stumbling, backfires/pops, idles drop real low and hunts, vibrations and usually stalls around 4-5 minutes after initial start.
Little bit of research leads me to think it's related to when the car moves from open loop fuelling to closed loop. Apparently the first 3 minutes is open loop as the O2 sensors haven't warmed up from cold, which makes sense. So I should be looking at oxygen sensors, coolant temp sensors as a start? No codes pulled for either. And which sensors would I change, if no codes are generated - pre cat or post cat? Thinking maybe my AOS has a weird issue too - did find a tiny bit of oil in the plenum. Planning to do a vacuum smoke test in the next day or two.
The weird thing is, I was driving home just fine, and while cruising at 60kmh all of a sudden the backfiring/misfiring started - would a bad sensor or AOS cause an issue like this while on the road?
Still determined to get this sorted out on my own... calling in a "professional" as last resort
(and yes, over last few months I've done a few ongoing repairs - oil change, oil pressure spring/piston, new fuel pump, new fuel pressure regulator, new alternator, new crank position sensor, coil packs/plugs/tubes, cleaned and checked MAF, IACV, throttle body, checked all fuses, battery tests good, checked all grounds)
At this point u will just be thowing parts at it with out a real good scanner that can log the data from the sensors. My guess is the maf, it causes a lot of funny things when it goes bad.
You could unplug the O2 sensors and start it cold to see if any change.
You might be able to do the same thing with the MAF unplugged, but to rule out components, just do one change at a time.
Unplug one pre-cat oxygen sensor at a time. You can leave both post-cat/monitoring oxygen sensors plugged in.
You could have an air leak somewhere that lets in unmetered air. During the first 3 minutes the cold start enrichment is enough to keep the engine running normally (higher idle than normal depending on amount of unmetered air and whether the idle control valve can compensate) despite the extra air from the intake leak.
Once the cold start enrichment is over then it could run so lean that the lambda control is no longer able to correct for it by injecting more fuel and the engine runs as you describe.
(Read in another post of yours that you have a 99 convertible auto and thus cable throttle and icv)
The lambda sensors are heated and are working after 30s. It's the cat convertors that require heating up before they start converting.
Durametric tool would be of great help here to monitor live sensor values
Thanks guys - noticed another thing - changed the starter motor today (bought this part ages ago) and did some electrical testing since I had good access to the Y cable etc.
Disconnected the battery from the car - I think there's a short or something strange as I'm getting some continuity from the positive battery terminal to ground! You'd think the positive terminal should be totally isolated from any grounds, right?
Might trace back the positive cable from battery to rear battery post and see if there's anything weird going on.
Quote: "You'd think the positive terminal should be totally isolated from any grounds, right?"
Answer: No, as between these terminals all electrics are connected.
You're basically measuring the resistance of all connected electrical parts like ecu's, bulbs, generator and everything else that is connected directly to the positive terminal and ground.
What we're you able to resolve thusfar?
