6 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHIntake vaccum at 680 rpm idle
Leading reported evidence
Use vacuum gage, sometimes more than one, up
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
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Performed · outcome unconfirmed
I've used a vacuum gage, sometimes more than one, up to 4 at a time, to set carbs, 1, 2 or more barrel carbs like Holley and Webers (2 2 barrel side drafts) and 4 individual cars on my Honda CB750 motorcycle, and other brands I've long forgotten.
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
PST2) or "Durametric" computers can instruct the vehicles computer to activate or deactivate variable camshaft timing at will (should I so chose to using those test functions).
Leading evidence: 'Use vacuum gage, sometimes more than one, up' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Test functions)' (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.
Suggestion · Original poster
PST2) or "Durametric" computers can instruct the vehicles computer to activate or deactivate variable camshaft timing at will (should I so chose to using those test functions).
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
For example, there are numerous ways one can use intake vacuum pressure to determine various engine issues such as timing, valves, piston rings, vacuum leaks, etc.
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
PST2) or "Durametric" computers can instruct the vehicles computer to activate or deactivate variable camshaft timing at will (should I so chose to using those test functions).
These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.
Test functions)
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
PST2) or "Durametric" computers can instruct the vehicles computer to activate or deactivate variable camshaft timing at will (should I so chose to using those test functions).
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
For example, there are numerous ways one can use intake vacuum pressure to determine various engine issues such as timing, valves, piston rings, vacuum leaks, etc.
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
PST2) or "Durametric" computers can instruct the vehicles computer to activate or deactivate variable camshaft timing at will (should I so chose to using those test functions).
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
I've used a vacuum gage, sometimes more than one, up to 4 at a time, to set carbs, 1, 2 or more barrel carbs like Holley and Webers (2 2 barrel side drafts) and 4 individual cars on my Honda CB750 motorcycle, and other brands I've long forgotten.
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.
6 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: 20261026T222516Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
IIRC one source is 0.4 to 0.6 bar. In IN of HG @ 32F this works out to 11.8 to 17.7.
Not sure what effect elevation has on this reading.
Why do you ask?
Sincerely,
Macster.
That's a pretty big range if you ask me, but you've been around longer than I, so who am I to say that.
FWIW my Ford F150 reads rock solid steady at 17.5 bar IN Hg.
I've read that elevation can affect the reading (starting around 2000 feet), since atmospheric pressure affects how many inches of mercury drawn by vacuum.
I'm taking some measurements to ascertain the health of my engine after top end rebuild and backing up other measurements such as crank case vacuum using slack tube manometer, leakdown and compression, and spark plug examination.
For example, there are numerous ways one can use intake vacuum pressure to determine various engine issues such as timing, valves, piston rings, vacuum leaks, etc.
Here is a slack tube manometer crank case vacuum reading at 680 rpm idle 93F ambient temp engine temp 197F 1800 feet elevation, appx. Pacific time, 2:30pm, waning crescent moon.
5 inches of water drawn from the crank case (and steady).
http://www.youtube.com/watch?v=axBNu1CWJyY
Oh, and THANKS for the reply, as always.
I've used a vacuum gage, sometimes more than one, up to 4 at a time, to set carbs, 1, 2 or more barrel carbs like Holley and Webers (2 2 barrel side drafts) and 4 individual cars on my Honda CB750 motorcycle, and other brands I've long forgotten.
You have to be a bit careful relying upon vacuum with these engines. The VarioCam system can render the vacuum readings while not meaningless, confusing.
The proper range of vacuum can vary depending upon the state of the VarioCam system and I believe if a vacuum reading wants to be taken the tech can command the VarioCom system to deactivate (or activate) and the factory engine manual will give him a vacuum reading or range of permissible readings.
Just a naked reading might be well, not all that useful.
Also, the engine controller will give you are clue as to the health of the engine by when it is operating performing a variety of tests some over a long period of time and others over a very short period of time. In the case of the latter, misfires.
If the engine controller doesn't detect any misfires the odds are high the engine's in pretty good health.
Sincerely,
Macster.
I too, with my "Porsche Service Tool 2" (a.k.a. PST2) or "Durametric" computers can instruct the vehicles computer to activate or deactivate variable camshaft timing at will (should I so chose to using those test functions).
With the 3.4L 1999 C2 996 M96-01 engine, there are two operating functions of variocam. On or off.
Without human intervention (below ~1500 rpm or above ~5500rpm) it is off or not grounded. At 680 rpm idle, one should expect static operation and affects of variocam operation, correct? (thereby assume that variocam operation is not affecting vacuum gauge readings - aside from perhaps a faulty ground, DME, wiring loom, voltage, exhaust issue, valve guide, actuator, solenoid, map, timing, leak, breech, NVRAM, or otherwise?).
https://rennlist.com/forums/996-foru...-a-primer.html
