Long sync time on crank sensor
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Re: Long sync time on crank sensor
The screen dump shows just 133 rpm max, that is very slow, is there a drop in hall crank sensor available?
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Re: Long sync time on crank sensor
The gap doesn't display correctly, there are two pulses instead of 1.stevieturbo wrote:@Alex
What on the scope trace suggests polarity may be incorrect ? I know on an actual oscilloscope the trace would show this, but on the DTA scope, what are the visuals on it ?
This is a 36-1 with the wires reversed:
This is a 36-1 with the wires reversed:
As you can see, identical crank trigger set ups, but location of gap affects what the ECU sees.
To be fair, the first one is quite common, the second one quite rare that nothing is seen at all.
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Re: Long sync time on crank sensor
The trigger is on the flywheel, and looks like this:
The sensor sits at 12-o-clock on the back of the engine as you can baely see in this photo:
I can see why you mention that the signal is inverted because the flywheel have valleys instead of peaks for the sensor ti trigger on.
I will try to get 2 scopes for you today.
Thanks for all the help, and good discussions this far
The sensor sits at 12-o-clock on the back of the engine as you can baely see in this photo:
I can see why you mention that the signal is inverted because the flywheel have valleys instead of peaks for the sensor ti trigger on.
I will try to get 2 scopes for you today.
Thanks for all the help, and good discussions this far
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Re: Long sync time on crank sensor
Okay, so I finally got around to get some new scope images. Reducing tooth factor to 1500 dramatically reduced cranking time! Tried 1800 and 1600, and felt i was the shortest at 1500.
Cold crank with tooth factor set to 2000:
Cold crank with tooth factor set to 1800:
Hot crank whith tooth factor set to 1600:
Hot crank when tooth factor set to 1500:
I forgot to save an image of hot crank@2000/1800
Cold crank with tooth factor set to 2000:
Cold crank with tooth factor set to 1800:
Hot crank whith tooth factor set to 1600:
Hot crank when tooth factor set to 1500:
I forgot to save an image of hot crank@2000/1800
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Re: Long sync time on crank sensor
Swap the pins 1 and 2 on the sensor, and try again.
You have holes rather than teeth, so everything is reversed.
You have holes rather than teeth, so everything is reversed.
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Re: Long sync time on crank sensor
I will try that. Should I set the tooth factor to 2000 then?Alex DTA wrote:Swap the pins 1 and 2 on the sensor, and try again.
You have holes rather than teeth, so everything is reversed.
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Re: Long sync time on crank sensor
I swapped the pins and set the tooth factor back to 2000. Starts as good as it did before on 1500
Gap tooth factor 2000 after reversing pin 1 and 2:
Gap tooth factor 1500 after reversing pin 1 and 2:
Just for reference, I uploaded another video on a hot start now. I still feel like it should be a little faster to start, but it's an old starter, so it might not turn the engine fast enough. And just having crank and no cam trigger might also add to a bit longer start?
When it gets sync it fires right up!
Video: https://www.youtube.com/watch?v=AGLNMyOhglw
And yes, I need to connect the tachometer. Just need to get a 1Kohm resistor first.
Gap tooth factor 2000 after reversing pin 1 and 2:
Gap tooth factor 1500 after reversing pin 1 and 2:
Just for reference, I uploaded another video on a hot start now. I still feel like it should be a little faster to start, but it's an old starter, so it might not turn the engine fast enough. And just having crank and no cam trigger might also add to a bit longer start?
When it gets sync it fires right up!
Video: https://www.youtube.com/watch?v=AGLNMyOhglw
And yes, I need to connect the tachometer. Just need to get a 1Kohm resistor first.
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Re: Long sync time on crank sensor
Bare in mind, slow to start, and slow to sync are two very different things.
Once sync'd, it should be able to start very quickly. If not sync'd...it wont start.
And polarity of a VR sensor must be correct, or ignition timing will be all over the place as revs change.
Once sync'd, it should be able to start very quickly. If not sync'd...it wont start.
And polarity of a VR sensor must be correct, or ignition timing will be all over the place as revs change.
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Re: Long sync time on crank sensor
I know. It fires right up when it gets sync. Takes less than .5sec.stevieturbo wrote:Bare in mind, slow to start, and slow to sync are two very different things.
Once sync'd, it should be able to start very quickly. If not sync'd...it wont start.
And polarity of a VR sensor must be correct, or ignition timing will be all over the place as revs change.
As Alex said earlier; The wiring was correct, but I don't know if he ment that is was correct for a trigger wheel with teeth or with holes. Or if the wiring matter for that reason.
It got better when reversing the wiring.
About the timing, that is something I need to take a look at. Timing seemed stable and good before.
What other things will help the ECU get sync faster?
Sorry for all my questions When i get to have a discussion with someone who knows what they are doing, I just want to absorb as much knowledge as possible
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Re: Long sync time on crank sensor
Those traces are now perfect.aleksanderk wrote:I swapped the pins and set the tooth factor back to 2000. Starts as good as it did before on 1500
Gap tooth factor 2000 after reversing pin 1 and 2:
Gap tooth factor 1500 after reversing pin 1 and 2:
Just for reference, I uploaded another video on a hot start now. I still feel like it should be a little faster to start, but it's an old starter, so it might not turn the engine fast enough. And just having crank and no cam trigger might also add to a bit longer start?
When it gets sync it fires right up!
Video: https://www.youtube.com/watch?v=AGLNMyOhglw
And yes, I need to connect the tachometer. Just need to get a 1Kohm resistor first.
Note - the gap tooth fact won't affect the trace. The gap tooth factor is set depending on what is in the trace.
You should get immediate sync with that trace.
If I've understood correctly, your sync issues are now sorted?