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Old 10-29-2009, 10:01 PM   #1
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Default Crank Wheel & VR Sensor

Installed crank wheel and VR sensor. I can watch the teeth get counted in TunerStudio, and I have a tach reading. Car acts like it wants to start (has spark and fuel), but just won't catch.

How can I tell if my VR sensor polarity is reversed? I know I can go swap wires around, just didn't want to damage perfectly good wiring with a a cut n splice if I didn't have to.

Also, the megamanual set up instructions differ from the Trigger Wheel Settings dialog box presented. I understand you turn the crank wheel such that cyl 1 is at TDC, then count the number of teeth between the missing teeth and the VR sensor. You enter this data for "tooth #1". I get that. But in the manual, they show using the tooth count. The dialog box in TunerStudio (and MT) look like they're asking for crank degrees. Input?
I tried both... Same result: No start.

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Old 10-30-2009, 12:15 AM   #2
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Also how do I know rising edge or falling edge? I haz no scope. (I tried both w/o success, though one way--I forget which-seemed like it was more apt to start).
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Old 10-30-2009, 03:17 AM   #3
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Ben, I can't help you with this one, but my only recommendation is that since you are walking in somewhat uncharted territory, you should in fact get a scope, even a single channel 10Mhz unit will do.

Jim
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Old 10-30-2009, 03:37 AM   #4
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Talk to patsmx5. He's running the same sensor and wheel on his 99 with MS and it works good afaik.
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Old 10-30-2009, 03:39 AM   #5
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not that I know anything about VR sensors, and it may just be the picture...but your VR sensor looks really far away from your trigger wheel compared to what i've seen on other cars.
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Old 10-30-2009, 04:09 AM   #6
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Rising / falling is not adjustable via software insofar as the primary trigger is concerned. The signal is going into the hardware IRQ pin on the CPU, which is fixed at falling edge detect (as measured at pin 14 of U1). Only the second trigger, which you should no longer be using, is adjustable in software for rising / falling.

You want the sensor and decode circuit configured so that the trailing edge of the gap is a falling edge. You will need a scope to visualize this. It should look like the yellow trace below, assuming an MS1:




I haven't really used TunerStudio yet, but basically you need to enter four tooth positions plus an offset in degrees.

The tooth positions tell it which tooth to use as the reference for both TDC and BDC, as well as which tooth to use as the "return", which is the one it'll fire on during cranking if you have cranking set to trigger return. The offset in degrees, if I recall correctly, tells it how far away from TDC / BDC the teeth you declared as the reference teeth are.

This is the least incorrect set of documentation on the subject I know of: http://www.msextra.com/manuals/MS_Ex....htm#wheeldecr


Nice looking setup, incidentally. Where'd you get the hardware?
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Old 10-30-2009, 09:44 AM   #7
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Quote:
Originally Posted by Joe Perez View Post
Nice looking setup, incidentally. Where'd you get the hardware?
+1

I'm looking to do the same thing with my new motor. I figure since my new motor will be out, I should do everything the right way before putting it in.

I also want to do a writeup on the trigger wheel and MS-II construction for my 92 motor a la Brain's writeup so other people don't need to endure the pain.
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Old 10-30-2009, 10:53 AM   #8
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Quote:
Originally Posted by wayne_curr View Post
not that I know anything about VR sensors, and it may just be the picture...but your VR sensor looks really far away from your trigger wheel compared to what i've seen on other cars.
Good eye sir. I took the picture before adjusting the sensor towards the wheel. It's now set with a gap equal to the thickness of a business card. TunerStudio has a logger where you can watch the MS read teeth, so I can confirm it reads the teeth and the missing teeth, and I have RPM registering on the dash tach.

Quote:
Originally Posted by Joe Perez View Post
Rising / falling is not adjustable via software insofar as the primary trigger is concerned. The signal is going into the hardware IRQ pin on the CPU, which is fixed at falling edge detect (as measured at pin 14 of U1). Only the second trigger, which you should no longer be using, is adjustable in software for rising / falling.

You want the sensor and decode circuit configured so that the trailing edge of the gap is a falling edge. You will need a scope to visualize this. It should look like the yellow trace below, assuming an MS1:

I haven't really used TunerStudio yet, but basically you need to enter four tooth positions plus an offset in degrees.

The tooth positions tell it which tooth to use as the reference for both TDC and BDC, as well as which tooth to use as the "return", which is the one it'll fire on during cranking if you have cranking set to trigger return. The offset in degrees, if I recall correctly, tells it how far away from TDC / BDC the teeth you declared as the reference teeth are.

This is the least incorrect set of documentation on the subject I know of: MSnS Extra Ignition Hardware Manual


Nice looking setup, incidentally. Where'd you get the hardware?


Joe, the MS2 set up is a bit different than the MS1 set up. All you need do is enter the number of teeth on the wheel, the number of missing teeth, turn the crank to cyl 1 TDC and count the teeth between the missing tooth and the sensor position*. The rest happens automajically.
*The part that's troubling me is the ms2 documentation show entering in this count in teeth, and in TS (Joe you should use TunerStudio; you will like it a lot) the dialog box asks for degrees. They call this "delay" teeth. So if I have 6 delay teeth on a 60 tooth wheel, do I enter 6 or do I enter 36 into the dialog box? Well I tried both, and neither starts the car. The same car that fired up immediately yesterday on the factory wheels.

The set up came from Frank's former Motec (now V8) car. I don't know who made the components originally, but they are very cool.

Quote:
Originally Posted by TrickerZ View Post
+1

I'm looking to do the same thing with my new motor. I figure since my new motor will be out, I should do everything the right way before putting it in.

I also want to do a writeup on the trigger wheel and MS-II construction for my 92 motor a la Brain's writeup so other people don't need to endure the pain.
If I can get the damn thing to start, you won't have to do that.

At this point, I'd say copy Patsmx5. He is running a Ford EDIS system. Once bolted and wired, using the EDIS system is as simple as picking "EDIS" from the ignition type menu.

Bah. I don't want to buy a damn scope.

Last edited by Ben; 10-30-2009 at 11:29 AM.
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Old 10-30-2009, 12:00 PM   #9
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I reversed polarity on the VR sensor leads. No change.
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Old 10-30-2009, 02:21 PM   #10
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Old 10-30-2009, 03:19 PM   #11
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Confirmed that you do enter the delay teeth value in degrees.
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Old 10-30-2009, 03:43 PM   #12
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Quote:
You have it configured to use the additional injectors but you don't have a cam sensor (single wheel with missing tooth). That means that you will have only 2 injectors which will fire. You need a cam sensor to have sequential injection and use all 4 injector channels.

Jean
Yes, I'm that damn stupid. Ugh.
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Old 10-30-2009, 04:59 PM   #13
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Car runs.
Batch fire FTW.
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Old 10-30-2009, 05:15 PM   #14
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Quote:
Originally Posted by Ben View Post
Joe, the MS2 set up is a bit different than the MS1 set up.
And if I'd have looked at your sig, I'd have noticed you're using an MS2. :retard:

Sorry, I've been helping another guy plan his MS1 VR setup, and have that set of code in my brain right now. Totally didn't even think to see if you were on MS2.

But congrats.

I do want to get into TunerStudio, I just haven't been home long enough to do much of anything recently. It will be necessary, as Jessica will be running full sequential when it goes back together.


BTW, buy a scope. Until you have one, you are half a man.
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Old 10-30-2009, 05:39 PM   #15
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I have no issues with buying a scope. I just would rather pick one up when I can snag a deal on something cheap.

I take it by another post of yours that you don't think an NA CAS on the back of the exh cam for the 2nd trigger will introduce any meaningful error.
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Old 10-30-2009, 05:45 PM   #16
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I don't think the acuracy of the 2nd trigger really matters at all. The ecu just uses it to determine what cycle it's in. As long as it gets the signal before the cycle starts, it should be ok. All the timing is still based off the crank trigger. At least that's what I think.

I use a CAS on the exhaust cam along with a 60-2 crank wheel with my Haltech to run sequential injection (on my Protege).

If you are that worried about error, you should be mounting the crank trigger on the rear of the pulley so that it's not "damped".

--Ferdi
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Old 10-30-2009, 05:51 PM   #17
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Dammit Ferdi, don't do that to me. Now I'm going to lie awake all night worrying about timing inaccuracy due to the harmonic damper.

I believe you are correct regarding the second wheel. There's a fella on m.net who modified an NA magnetic CAS to replicate the output of the NB cam sensor. I think I might give that a shot, but use both wheels to output one to each computer. That would enable me to run a cut cam cover and install adjustable gears. WOOT.
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Old 10-30-2009, 07:24 PM   #18
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Ben,
You're not threaded in on the inner wheel? Only the out bit is rubber. I think you should be fine. I welded one to a friend's wheel, worked ok till he switched over to my little card.

Did you get up and running, then, with the stock sensor? You're running parallel for emissions? I would STRONGLY suggest using the stock sensor. Its there and ten minutes of wiring should have you working. Even if only for the cam signal.

One more thing: I haven't done it, but I know folks who have - you can get software oscopes - you use your computer's sound card, plug a headphone into the mic or line in port and cut the wires off. Should get two channels of at least 40 kz bandwidth that way. Enough for looking at crank teeth.
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Old 10-30-2009, 07:32 PM   #19
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I'm not really worried about it. It's bolted to the crank pulley in 4 locations around the big nut.

It runs great with the stock sensors standalone. Parallel it ran great, but threw codes. The car must pass obd emissions, and I already had the crank wheel. It was easier than dealing with trigger circuits, as I don't have the supplies and possibly the ability to build them.

The 60 tooth wheel should be more precise than the stock wheel anyway, I'm cool with running it. I wouldn't mind being able to share the cam sensor signal one bit.
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Old 10-30-2009, 08:27 PM   #20
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I think that's the way to go. Post more details (pics/source/mounting method) on the crank wheel. This is something I've wanted to do and been asked to help with several times!
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