Ignition Problem?

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.
 
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.
 
Failure at 4k rpm, a resonent freq. For a 4 cyl. Engine. I looked at the malfunction codes for engine knock and it appears it only reports that it sees the sensors and nothing if a knock occurs. Saw nothing to define how ecm functions if to a is seen. Poor starter valve sync could couse the engine to knock. Asses the quality of the sync by looking at the heads at the header pipes with a laser heat gun. A big temp difference between cylinders states poor balance.
 
ST_Jim said:
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.
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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.).


Sent from my iPhone using Tapatalk Pro
 
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Jim Van said:
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
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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
 
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They may get cheaper somebody just released a competing 4 channel entry level one with all the serial sniffing software included. It's worth having a look around on the interwebs, eevblog on youtube etc.
It's pretty common for a 50mhz model to have the same front end as their 100mhz version. It's pretty easy (as in intended unofficial sales feature) to tweak it to unlock the full bandwidth on some.
 
dwalby said:
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
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A BIG +1 !!

I Googled " 4 Channel Ocscilloscope" but didn't find this. Thanks, Doug. I will keep this in mind. Then all would be needed is the Hantek HV clamp for the ignition wire and a current probe.
 
The interesting thing about Rigol is the Bandwidth is determined via a SW key. So you can buy the 50 MHz version, and put a key in to enable wider bandwidth. They also have Mixed Signal versions with more digital inputs (like a logic analyzer), and also adding a signal generator. Some scopes can also decode serial stuff like I2C, SPI, RS232, and I think even Can-bus.

If you're curious about such things, and how to get a key, you might take a look see at http://www.eevblog.com/forum/

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. ;-)


Edit:

BTW, TEquipment.net offers a small discount (~6% or so?) for EEVblog forum members. Sign up and search for a thread to ask for a PM with the discount code - or even ask the TEquipment rep and they'll probably just give it to you for mentioning EEVblog. I bought a Fluke 87V from them 6 months ago and used it (but I can't seem to find the code now, so don't ask me!)
 
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ST_Jim said:
I'd rather have a 34401A. ;-)
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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.
 
While looking over the list of what you have done to date it occurred to me that everything that has been tried is mostly related either to electrical or drive-ability/emissions. Have you considered the possibility that there maybe a mechanical problem that is manifesting itself as an ignition/fuel problem? As an example of what I mean older cars that had distributors with worn distributor shaft bushings often exhibited what appeared as ignition problems as they misfired, pinged, lacked power, etc. because the ignition timing was jumping all over the place. These were the symptoms however. The cause of the problem was mechanical- the worn distributor bushings. Unfortunately I do not have a brilliant idea to offer you of a mechanical anomaly that would cause your specific issue. If you haven't already eliminated everything mechanical however, it might be worth giving it some consideration.
 
dwalby said:
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.
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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. :)
 
dwalby said:
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. :)
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But, like the guy with two clocks who is no longer certain of the time... :D


Enjoy your new toy.
 
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