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| A cam sensor idea I never expected to work, but it does... https://mail.slantsix.org/forum/viewtopic.php?t=65942 |
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| Author: | Dart270 [ Fri Apr 30, 2021 3:28 am ] |
| Post subject: | Re: A cam sensor idea I never expected to work, but it does... |
Hi Ed, I would think any misfires or mistriggers of the crank sensor during running would cause the ECU to lose phase. It would seem the ECU would best read the cam sensor regularly, if not every crank cycle. It's not critical for running, but then the sequential injectors would not be in the desired phase with the engine cycle if there were mistriggers. Lou |
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| Author: | MadScientistMatt [ Fri Apr 30, 2021 6:54 am ] |
| Post subject: | Re: A cam sensor idea I never expected to work, but it does... |
Quote: I may be wrong, but don't most ECU ignore the cam position sensor once they've already figured it once during start.......
The MS3 is set so that in missing tooth wheel mode without VVT control, it will use the cam sensor for determining engine phase at startup, then ignore the cam sensor after phase has been established until the engine loses sync with the crank trigger. With the missing tooth wheel mode, the MS3 already has a positive way of telling if it has been able to maintain sync or not - it's virtually impossible to get a noise pattern that would maintain sync by accident.So if the signal is good enough during starting for the ECU to figure out where the engine is in it's cycle, you're good to go. Some other spark modes require checking the cam signal every crank revolution - sometimes because the spark mode requires it and sometimes because coding in the cam signal ignoring behavior would add complications. I can't speak for how other ECUs handle this. |
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| Author: | Dart270 [ Fri Apr 30, 2021 7:21 am ] |
| Post subject: | Re: A cam sensor idea I never expected to work, but it does... |
Great, thanks for clarifying, Matt. I was not considering an algorithm that would use the missing tooth wheel that way. Makes perfect sense. Lou |
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| Author: | Greg Ondayko [ Fri Apr 30, 2021 10:29 am ] |
| Post subject: | Re: A cam sensor idea I never expected to work, but it does... |
So My question is would the fuel pump node work for triggering in Full sequential mode? Sequential spark and Injection? I have 6 coils on Ruster but they are currently wasted spark. Greg |
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| Author: | Dart270 [ Fri Apr 30, 2021 11:33 am ] |
| Post subject: | Re: A cam sensor idea I never expected to work, but it does... |
I figured that was the whole idea. Matt can confirm. Lou |
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| Author: | emsvitil [ Fri Apr 30, 2021 3:01 pm ] |
| Post subject: | Re: A cam sensor idea I never expected to work, but it does... |
I was just trying to determine if the fuel pump lobe was 'good enough' so there would be no need to grind away at it.......... |
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| Author: | MadScientistMatt [ Wed May 05, 2021 5:08 am ] |
| Post subject: | Re: A cam sensor idea I never expected to work, but it does... |
Correct, it will work without modifying the lobe when combined with a 36-1 crank trigger. |
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| Author: | Pierre [ Sat Jun 26, 2021 12:07 pm ] |
| Post subject: | Re: A cam sensor idea I never expected to work, but it does... |
Oooo... how simple. Is there a software offset for the angle, or is the peak of the lobe at the right place to trigger the sensor at tdc? |
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| Author: | Dart270 [ Sun Jun 27, 2021 3:42 am ] |
| Post subject: | Re: A cam sensor idea I never expected to work, but it does... |
All it needs is sync with the cam to start. The 36-1 crank wheel will give the sync needed to run everything after that, and there is (must be, haven't played yet) a phase angle for that. Lou |
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| Author: | Pierre [ Sun Jun 27, 2021 11:14 am ] |
| Post subject: | Re: A cam sensor idea I never expected to work, but it does... |
There definitely is an offset for the crank - I’m using it now on the 36-1 crank wheel with edis modules. I guess the cam lobe can be at any point as long as its position is known and can be accommodated for. |
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| Author: | MadScientistMatt [ Tue Jun 29, 2021 2:15 pm ] |
| Post subject: | Re: A cam sensor idea I never expected to work, but it does... |
The software just checks for "Did the cam signal show up before the missing tooth this time, or didn't it?" It does not do any more sophisticated check unless you're trying to actively monitor a variable valve timing system. |
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| Author: | Pierre [ Wed Jun 30, 2021 12:30 am ] |
| Post subject: | Re: A cam sensor idea I never expected to work, but it does... |
Just read through the section of the manual. There’s a “best” position but apparently nothing is mandatory. Still can’t wrap my head around it. If it can be in any position … what’s so good about the “best” position? Less time cranking until synch? Or is there a limit to the position flexibility…. Maybe anywhere within +/- 90deg of tdc-exhaust? |
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| Author: | MadScientistMatt [ Wed Jun 30, 2021 7:21 am ] |
| Post subject: | Re: A cam sensor idea I never expected to work, but it does... |
Quote: Just read through the section of the manual. There’s a “best” position but apparently nothing is mandatory. Still can’t wrap my head around it.
The only position you can't put the cam sensor in is lining up the active edge with the missing tooth. Anything else, one spot is pretty much as good as another.
If it can be in any position … what’s so good about the “best” position? Less time cranking until synch? Or is there a limit to the position flexibility…. Maybe anywhere within +/- 90deg of tdc-exhaust? |
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| Author: | emsvitil [ Wed Jun 30, 2021 1:57 pm ] |
| Post subject: | Re: A cam sensor idea I never expected to work, but it does... |
Just out of curiosity, where is the fuel pump lobe in relation to cylinder one TDC ignition cycle? |
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| Author: | Dart270 [ Thu Jul 01, 2021 4:18 am ] |
| Post subject: | Re: A cam sensor idea I never expected to work, but it does... |
Gosh, now I need to go look at some cams... Lou |
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