8 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHDurametric rich at idle, lean at cruise
Leading reported evidence
Replace adaptation values
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
My suspicion comes from the changing adaptation values.
Leading evidence: 'Replace adaptation values' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Replace adaptation values' (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.
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 would assume that the computer attempts to settle towards a somewhat stable adaptation over time if there are no changes otherwise.
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
One of the reasons is because the RKAT and FRA seem to change quite a bit.
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
One question is whether adaptation can change so much if nothing else is changed.
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.
8 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: 20261026T165820Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
Runs well overall with no misfires.
Started with the following:
New MAF.
New upstream oxygen sensors.
Used to be lean at idle but now smoke test shows no leak and pulling the oil filler cap definitely affects engines speed.
Can a bad fuel pressure regulator result in rich idle, lean cruise?
Can a lean cruise affect the lower range so that RKAT is rich in an attempt to compensate?
Seems like fuel pump insufficiency problem might not show up as a lean idle condition but it probably doesn't explain why the idle is rich.
We have seen a bunch of junk electrical components, including MAF sensors lately.
I now test my spare electrical components so I know they’re good.
Instead of throwing more parts at the issue, let’s diagnose the issue.
You have a Durametric, so you should be able to see what the sensors are reporting.
What does the MAF report at idle & cruising?
[Image-only post; no author-written text. Original image references:]
https://cimg7.ibsrv.net/gimg/rennlist.com-vbulletin/2000x1504/pxl_20230406_004649135_b6a2fc11e226a7f6559653312bb9a5dad8625ba3.jpg
Not surprised you mentioned that. I'm actually suspicious of the mass air flow sensor also.
One of the reasons is because the RKAT and FRA seem to change quite a bit. I'm not sure how to interpret that kind of change when there has been no difference otherwise.
Do adaptations tend to change a lot? And how long do they take to be established after a reset? One post I read here from some time ago suggested that 15 minutes of driving is sufficient. I have no idea if that is correct or if there can be significant change in adaptation over 500 mi. I would assume that the computer attempts to settle towards a somewhat stable adaptation over time if there are no changes otherwise.
The Boxster MAF's from the 2.5's were bad out of the box last year from Bosch- I had to take each new one out and test it in a car I had here before sending them to customers. The issue was very obvious in the Boxster without plugging anything it, hunting idle, stumbling etc.
Not sure if that carried over into 996 world.
--Aaron
Thanks Rennpart/Aaron.
Car is idling fine.
My suspicion comes from the changing adaptation values.
One question is whether adaptation can change so much if nothing else is changed. Shouldn't it become somewhat stable?
It looks like it goes from adding fuel after a reset to subtracting fuel at idle within a week or two and a few hundred miles. Hard to imagine that any air leak would slowly resolve after four or five drives.
Reset and clear codes followed by standard half an hour drive including city and freeway to 80 miles an hour gives the following:
RKAT and FRA now suggest lean, is that correct?
According to previous threads 15 minutes should be enough to establish adaptation but I have not seen that confirmed.
Here it is half an hour earlier immediately after clearing the codes And before taking a standard drive including town and freeway.
Idle may be a little high but remember this is immediately after clearing codes. Has not yet adapted.
FRA is close to one. RKAT is zero. As designed.
This is a source reference. Confirm exact model applicability in the original material.
