NB Cam Angle Sensor Heatsoak/Failure
05-01-2016, 08:17 PM
#141
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Join Date: Oct 2012
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Sorry for the tardy reply, I had family in town this weekend!
I'm frankly not entirely sure about the resistor. I don't have your circuit (what does Rev use? You could check with him on this). I think I used a 1k pull up in my testing - the highest value that works consistently is the right answer. I would say start without worrying about it, revisit if it's not working. You could also see if it's getting hot - but I don't think it will. Measuring the current draw is likely a great place to start.
There is a little something to this. Anything will work, but I think you can do a bit better.
In short, you want the missing tooth to be somewhere sane (a few teeth before the earliest you'd even have an ignition event - thought they are only 15 teeth apart anyway) - and of course, since the sensor is at about 5 pm angle on the crank pulley, that's where it needs to be (so call it 90* from vertical when the motor is at TDC #1.
You also want to make sure the poll has happened before that ignition event. The poll should happen at/just after the missing tooth (otherwise you have to wait a while for it to come around). Keep in mind the cam moves with VVT, so basically, at full advance, you want SOMETHING like this:
Trailing edge of short cam tooth to be clear of the sensor when your "read" comes up - telling Tuner Studio how many teeth after missing tooth to make the read. I'd shoot for 1, or 2. Pick that position to be in the middle of the long tooth (I think I went with 57* "poll tooth width" on this one) at the Xth tooth after the gap.
Does that make sense conceptually? I can get some numbers together as long as the process sounds reasonable, and you know what wheel you're using. In real life, I based it largely off where the stock wheel was - marking cam with awl (and original cam wheel, in case I need to put it back) then used that to orient the wheel.
You have some 15* of slop I think, and you can look up the "right" tooth from the logs once you get it all assembled. Any misalignments here will only cost you fractions of a second on start up - everything else you can fix in software.
Let me know if I'm making sense, and I'll get you some numbers when I do. You're going to use the protege wheel?
I'm frankly not entirely sure about the resistor. I don't have your circuit (what does Rev use? You could check with him on this). I think I used a 1k pull up in my testing - the highest value that works consistently is the right answer. I would say start without worrying about it, revisit if it's not working. You could also see if it's getting hot - but I don't think it will. Measuring the current draw is likely a great place to start.
There is a little something to this. Anything will work, but I think you can do a bit better.
In short, you want the missing tooth to be somewhere sane (a few teeth before the earliest you'd even have an ignition event - thought they are only 15 teeth apart anyway) - and of course, since the sensor is at about 5 pm angle on the crank pulley, that's where it needs to be (so call it 90* from vertical when the motor is at TDC #1.
You also want to make sure the poll has happened before that ignition event. The poll should happen at/just after the missing tooth (otherwise you have to wait a while for it to come around). Keep in mind the cam moves with VVT, so basically, at full advance, you want SOMETHING like this:
Trailing edge of short cam tooth to be clear of the sensor when your "read" comes up - telling Tuner Studio how many teeth after missing tooth to make the read. I'd shoot for 1, or 2. Pick that position to be in the middle of the long tooth (I think I went with 57* "poll tooth width" on this one) at the Xth tooth after the gap.
Does that make sense conceptually? I can get some numbers together as long as the process sounds reasonable, and you know what wheel you're using. In real life, I based it largely off where the stock wheel was - marking cam with awl (and original cam wheel, in case I need to put it back) then used that to orient the wheel.
You have some 15* of slop I think, and you can look up the "right" tooth from the logs once you get it all assembled. Any misalignments here will only cost you fractions of a second on start up - everything else you can fix in software.
Let me know if I'm making sense, and I'll get you some numbers when I do. You're going to use the protege wheel?
HI, yes I am planning to use the Protege wheel. I will check with Rev on the resistor and the circuit he uses.
Can you recommend some guidelines to physically position the new cam wheel on the cam, perhaps based on the position of the OEM cam wheel before it is removed? As you mentioned, marking the cam and OEM cam wheel before removing the OEM cam wheel would provide a reference point. The question is how should the new cam sensor wheel be positioned on the camshaft, relative to the original position of the OEM cam sensor wheel/teeth?
EDIT: Thought throught the process overnight... Sounds like one should install the new crank wheel first and position the crank/engine so that it is 1-2 teeth past the missing tooth (relative to the crank position sensor). Assuming that the timing belt is on and the cams are timed properly, mark the intake cam so that one can install the new cam wheel with the long tooth in the middle of that mark. Once the new cam wheel is installed and the timing belt re-installed/cams times, the exact relationship of the "1-2" teeth vs the middle of the long cam tooth can then be seen in the TS composite logger. Am I on the right track with the process or missing the boat completely?
Thank you
Last edited by noname4me; 05-02-2016 at 08:35 AM.
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05-03-2016, 03:47 PM
#142
Absolutely dead on. That's what I did and pretty much what I was going to do just to tell you what I did.... But due to some non-traditional turbo plumbing getting my valve cover off is a bit of a process and I've been delaying.
I'd make one small suggestion: The cam locks to full retard with a spring loaded pin when there's no oil pressure - give that, you can take advantage of knowing where you are to set the angle, making sure you'll never accidentally pick up the short tooth.
If you're not feeling pretty confident, let me know, I'll dig into stuff (like double checking how far everything moves, how much slop you have, etc), but I think you're right on. If you can take some pics while you do it, it'd likely help. My wheel isn't mounted normally (it's modded to match the FM/949 2 missing tooth wheels), either, so I'd have to fake my pictures. :-)
-Abe.
I'd make one small suggestion: The cam locks to full retard with a spring loaded pin when there's no oil pressure - give that, you can take advantage of knowing where you are to set the angle, making sure you'll never accidentally pick up the short tooth.
If you're not feeling pretty confident, let me know, I'll dig into stuff (like double checking how far everything moves, how much slop you have, etc), but I think you're right on. If you can take some pics while you do it, it'd likely help. My wheel isn't mounted normally (it's modded to match the FM/949 2 missing tooth wheels), either, so I'd have to fake my pictures. :-)
-Abe.
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