12 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHBizarre Tach Problem
Leading reported evidence
Use separately
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
Starter seems fine....my guess is that since the car was completely disassembled for 9 months and the engine and transmission were procured used separately that it was likely some debris that was already there.
Leading evidence: 'Use separately' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'cps magnets picked up some metal shavings' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Check rpms against an obd-ii dongle and phone app' (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 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 · Original poster
So here is the update....probably the cps magnets picked up some metal shavings from the rebuild or being open for several months...looks like these particles could change magnetic readings....so i think your suggestions were a good place to start...will see if it happens again.
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
Try checking the RPMs against an OBD-II dongle and phone app.
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 hate recommending throwing parts at a problem without a diagnosis first but it would be a cheap thing to check with your fingers crossed..
Recommend throwing parts at a problem without a diagnosis 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.
Suggestion
I hate recommending throwing parts at a problem without a diagnosis first but it would be a cheap thing to check with your fingers crossed..
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
Starter seems fine....my guess is that since the car was completely disassembled for 9 months and the engine and transmission were procured used separately that it was likely some debris that was already there.
These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.
cps magnets picked up some metal shavings
No successful repair reported for this finding.
0
Identified cause
1
Suspected cause
0
Reported fixes
Read evidence and context
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 · Original poster
So here is the update....probably the cps magnets picked up some metal shavings from the rebuild or being open for several months...looks like these particles could change magnetic readings....so i think your suggestions were a good place to start...will see if it happens again.
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.
12 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: 20261026T161109Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
The following has happened twice to me on the same sweeping left hand highway entrance when I accelerate up the ramp....The tack jumps up 2000 rpm over what it should read and stays about 2000 high until I restart the car and then everything is normal again. I would just swap the instrument cluster but I had this one programmed to the correct mileage of my car and also had the face plates all converted to yellow so I don really want to replace it long term. Another problem is I am about ship the car to Laguna seca for a bucket list track event in november with some other firends. I don't want the tach giving me the wrong readings....Any suggestions on what the issue may be and is it even fixable.
The Crankshaft Position Sensor (CPS) is what reads your engine RPM and sends data to the Tachometer. Curious it would not throw a code as I know the CPS is famous for creating issues for owners when they fail. They are pretty cheap and you should be able to get a new one before your track day. I hate recommending throwing parts at a problem without a diagnosis first but it would be a cheap thing to check with your fingers crossed..
I don't think it's the TPS. That sensor either works or it doesn't when it doesn't the engine shuts off. But if it is old, it is worth replacing. If you do, cut the wire open and peel back the outside insulation that covers all the wires and then, check out the insulation on the individual wires. Mine were cracked beyond belief.
Wyovino's suggestion is really excellent because I just remembered you have your Dundon Frankenporsche which likely needed some trickery to get the stock instruments to talk to the M97. There could be something funky going on with that communication. I'm glad you got the CPS as a safety since it's cheap and returnable, but see if your mechanic can take a look at communications between the instrument cluster and the car. I'm wondering if your sweeping left causes some wires to come into contact due to inertia that causes some funkyness (technical term.)
So here is the update....probably the cps magnets picked up some metal shavings from the rebuild or being open for several months...looks like these particles could change magnetic readings....so i think your suggestions were a good place to start...will see if it happens again.
Thanks again for your helps....i will report back if anything changes
Starter seems fine....my guess is that since the car was completely disassembled for 9 months and the engine and transmission were procured used separately that it was likely some debris that was already there. Will keep an eye on it though.
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