The TPS is an input to the ECM, the "meter unit" is an output from the ECM, so any trash on the "meter unit" is not a factor, because it's not on an input. That's the way ECM's work.
I did hunt down and disconnect the lead from the ECM to the tach. No difference. As mentioned above the tach and the rest of the panel is driven by ECU, i.e. an output. The ~4000 RPM thing is I believe associated with the ECM changing from open to closed loop operation. If it were a resonant vibration I would expect the misfire to occur regardless of engine temperature, but it only occurs sometime, minutes or so after all three temp bars are present. No misfire prior to that or any other open loop operation (above 4K RPM, hard throttle, etc.).FYI, Jeff's ECU has been swapped with known good units, with no success. Missfire stays with the bike, not the ECU. I don't think he's tried swapping speedometer units.
Me thinks you retired from an electronic engineering role or something like that!FYI/BTW : I found this doing a Google search. You can buy these for about $200 online. A super troubleshooting tool especially for bikes with an ECM.
http://www.hantek.com/en/ProductDetail_13_10163.html
for $200 a decent bang for the buck. In Jeff's case the scope trace quickly identified the nature of the problem, but without any technical support from Honda the root cause of the problem is still a mystery. All the test equipment in the world isn't enough if you don't know what you're looking at with a proprietary design.FYI/BTW : I found this doing a Google search. You can buy these for about $200 online. A super troubleshooting tool especially for bikes with an ECM.
http://www.hantek.com/en/ProductDetail_13_10163.html
A BIG +1 !!for $200 a decent bang for the buck. In Jeff's case the scope trace quickly identified the nature of the problem, but without any technical support from Honda the root cause of the problem is still a mystery. All the test equipment in the world isn't enough if you don't know what you're looking at with a proprietary design.
edit: was searching on something else and stumbled upon this scope, for $350 I'd probably prefer it over the $200 one. Man, scopes sure have gotten cheap over the years.
https://www.tequipment.net/Rigol/DS1054Z/Digital-Oscilloscopes/?rrec=true
Hey Jim, what kind of work do you do?I get spoiled at work by Tektronix and HP/Agilent/Keysight scopes. At home I now have a hard time using my old Hitachi 60MHz analog scope. ;-)
Because it didn't work the first time I did that? [emoji6]Replace the O2 sensors and inspect wiring and plug connections. Not uncommon for them to fail.
I get spoiled at work by Tektronix and HP/Agilent/Keysight scopes. At home I now have a hard time using my old Hitachi 60MHz analog scope. ;-)
I'd rather have a 34401A. ;-)speaking of HP/agilent, go pick this up for $40 out in Oxnard, sounds a little too good to be true, but its been on CL for almost a month:
https://losangeles.craigslist.org/sfv/ele/d/hp-3478a-digital-multimeter/6374811014.html
why do you need 6.5 digits? Those also cost a LOT more than the 3478. I can't come up with a reason to even need 5.5 digits, but for $40 if its even close to being in calibration it would be worth it. If I lived closer I'd be a buyer, but don't feel like riding 200 miles each way to pick it up.I'd rather have a 34401A. ;-)
I just called the guy and he's going to ship it to me for $10, so I bought it. Now I'll be able to measure the voltage on my ST battery to 4 decimal places.why do you need 6.5 digits? Those also cost a LOT more than the 3478. I can't come up with a reason to even need 5.5 digits, but for $40 if its even close to being in calibration it would be worth it. If I lived closer I'd be a buyer, but don't feel like riding 200 miles each way to pick it up.
But, like the guy with two clocks who is no longer certain of the time...I just called the guy and he's going to ship it to me for $10, so I bought it. Now I'll be able to measure the voltage on my ST battery to 4 decimal places.