- Sun Apr 11, 2021 8:13 pm
#49551
This is killing me. I can't seem to pinpoint how to solve the noise issue I have while cranking. If you've read my other threads, I've had some nagging issues with re-start once I get running. More particularly cold start. Thinking it was tuning, I figured I just needed to adjust some things. But after looking into it more, I checked some logs and found my RPM reading would suddenly drop to 0 and return again. So hooking up an O-scope, I noticed the 12v rail, 5v rail, and trigger signals get these spikes in their waveforms. All signs point to the starter being the noise maker. I've tried different starters, but non have helped the issue.
I messed with some ferrite cores, beefed up my main ground to the motor, chassis, and battery, added some more capacitance to the 5v rail. All helped a lot but most effective was moving the coil grounds to the chassis instead of to the motor. But even with all this, I still seem to get the spikes occasionally. I'm fairly knowledgeable, but I'm floundering here. When I think I have it pegged, I'll switch things back to normal to check I've really solved it and sure enough, I get a random spike again.
I should add, before I tried to fix the problem, the amount of noise was far greater than what I get now. But I have a hard time believing I can't keep the noise down to a minimum level consistently and not stop the sync loss and RPM drop.
Screenshots are of a running tooth log, and megalog view of the rpm drop. Unfortunately I don't see any data while cranking of the tooth log. And I also added a screenshot of the scope. I'm out of ideas at this point...anyone who can help, I'd be greatful!
I messed with some ferrite cores, beefed up my main ground to the motor, chassis, and battery, added some more capacitance to the 5v rail. All helped a lot but most effective was moving the coil grounds to the chassis instead of to the motor. But even with all this, I still seem to get the spikes occasionally. I'm fairly knowledgeable, but I'm floundering here. When I think I have it pegged, I'll switch things back to normal to check I've really solved it and sure enough, I get a random spike again.
I should add, before I tried to fix the problem, the amount of noise was far greater than what I get now. But I have a hard time believing I can't keep the noise down to a minimum level consistently and not stop the sync loss and RPM drop.
Screenshots are of a running tooth log, and megalog view of the rpm drop. Unfortunately I don't see any data while cranking of the tooth log. And I also added a screenshot of the scope. I'm out of ideas at this point...anyone who can help, I'd be greatful!
Attachments
20210411_161536.jpg (1.73 MiB) Viewed 6970 times
Megalog Cranking.png (144.09 KiB) Viewed 6972 times
Tooth log Running.png (114.74 KiB) Viewed 6972 times