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Old 11-02-2021, 12:39 PM   #1
floydilian
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Default B20 MS2 would appreciate CAS advice

Hi ya'll! I'm moving my engine build over here from the restoration forum section as I'm deep into my Megasquirt build. I saw the other post about CAS wiring and wanted to pick the brains of the folks here - I too followed the rabbit hole of searching and found that a lot of CAS information had been deleted from the forums. Would appreciate any guidance for jumpers, wiring, etc!

Engine: B20
MS: MS2/Extra 3.4.3
CAS: Yoshifab adapter with aftermarket CAS
IAT: GM sensor
CLT: Bosch sensor, calibrated
MAP: MS2 onboard sensor to intake
Spark: Wasted spark with VW coil pack, mods done on MS2 board (correctly, hopefully)
Fuel system: Stock D-jet, flow tested and pressure tested
Wideband: AEM wideband

As it currently sits on my engine run stand:


Wiring:


CAS. I'm not sure which disc to use? I believe the one in the CAS is the correct one.


I've read all the MS documentation and forums posts but I am not quite getting it. Can anyone help me answer these questions?
Wheel: Is the wheel in the CAS the best one for MS?
Wiring: I believe the wiring is as below from the documentation for the 4G63 wheel

Pullup resistors: Can anyone confirm that these are needed? Documentation says "Electrically, the two signals on these CAS are connected the same as a hall sensor and require a pair of pull-up resistors in the wiring harness." Does anyone have a 'pullup resistors for dummies' link? When it says a pair, does it mean on each of the 2 hall sensor wires?
Jumpers on board: I believe none are needed. Can anyone share their setup?
Any other advice or sh*t I'm not thinking about?

Thanks so much in advance for any advice. I'm really enjoying this process.
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Old 11-02-2021, 07:20 PM   #2
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From your picture, it looks like you have a special brand new pandemic edition of the MS-2 with a v3.57 PCB (special being tall non-anodized case due to supply chain delays and shortages), correct?

The disc in your hand is the one you want - the other one is a 4G63 factory disc for a Mitsubishi or Hyundai. You have a B20, which (I believe?) rotates the disc in the opposite direction as a B21/B23/B230. If so, the orientation shown in your picture is correct.

To swap the disc, undo just the center bolt, remove the washers, and slide the disc out sideways. Aligning the flat of the D closest to the black sensor makes it a bit easier.

You can think of a pullup resistor as a helper spring, but for electrical circuits. For the CAS, you want 2 separate 1K ohm resistors to help the tach and cam signals swing from 0volts all the way up to 5volts:
- one connected between the CAS inner/cam signal and MS +5Vref
- one connected between the CAS outer/tach signal and MS +5Vref
Without the pullup resistors, the tach and cam signals would barely move from 0volts. The resistors can go in the wiring harness, or within the MS2 box.

The order of the pins in your picture is correct - when viewing the connector sticking out of the CAS, the pins from left to right are:
- ground
- +12v during run and start
- tach signal (outer disc sensor)
- cam signal (inner disc sensor)
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Old 11-03-2021, 10:39 AM   #3
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When removing the disc, dont be tempted to remove the 2 screws in the sensor. If that is pried up at all there is a good chance that you will damage the sensor.
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Old 11-03-2021, 12:27 PM   #4
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Quote:
Originally Posted by bobxyz View Post
From your picture, it looks like you have a special brand new pandemic edition of the MS-2 with a v3.57 PCB (special being tall non-anodized case due to supply chain delays and shortages), correct?
Exactly right - I think its the MS-2 in a a special box. Shiny and brand new.

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Originally Posted by bobxyz View Post
The disc in your hand is the one you want - the other one is a 4G63 factory disc for a Mitsubishi or Hyundai. You have a B20, which (I believe?) rotates the disc in the opposite direction as a B21/B23/B230. If so, the orientation shown in your picture is correct.
That makes sense based on the packaging when I bought secondhand but new on Ebay. I'll take your and cwdodson88's advice to remove the disc (not sensor) carefully! I'll verify the rotation, to be honest, it hadn't even occurred to me to consider the orientation of the disc.

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Originally Posted by bobxyz View Post
You can think of a pullup resistor as a helper spring, but for electrical circuits. For the CAS, you want 2 separate 1K ohm resistors to help the tach and cam signals swing from 0volts all the way up to 5volts:
- one connected between the CAS inner/cam signal and MS +5Vref
- one connected between the CAS outer/tach signal and MS +5Vref
Without the pullup resistors, the tach and cam signals would barely move from 0volts. The resistors can go in the wiring harness, or within the MS2 box.
Thank you for this explanation. I'm keeping track of all the steps and lessons learned since I think it has been a while since anyone has posted a D-jet to MS conversion with pics, etc, and this explanation will be really helpful there.

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Originally Posted by bobxyz View Post
The order of the pins in your picture is correct - when viewing the connector sticking out of the CAS, the pins from left to right are:
- ground
- +12v during run and start
- tach signal (outer disc sensor)
- cam signal (inner disc sensor)
Wonderful - thank you. I'll add the pullups to the CAS wiring and wire as you suggest.
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Old 11-03-2021, 07:03 PM   #5
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Quote:
Originally Posted by bobxyz View Post
You have a B20, which (I believe?) rotates the disc in the opposite direction as a B21/B23/B230. If so, the orientation shown in your picture is correct.)
I just asked this question in the CAS thread. So the ohv B20/30 rotates opposite and the disc works as shown in this thread. I already flipped it, so I need to put it back, I guess.
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Old 11-03-2021, 09:29 PM   #6
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I take back what I said about the disc orientation for a B20 - I don't know how the Yoshifab B20 adapter is machined nor what disc and slot alignment should be used. My guess would be that the disc should be flipped, and the distributor gear (to aux shaft) aligned so that the long slot in the CAS disc is centered underneath the black sensor (or maybe a bit left of center) when at TDC, but that's just a guess. If you have a new B20 CAS, I'd ask Yoshifab for guidance.

While the Tooth #1 angle and the rising/falling edges can be changed in MS to work with most alignments, it's easier if you can use a starting alignment that's close enough to work with the standard MS setup configs.

BTW: the original text from the first few posts of the DSM CAS Guide can still be found through the wayback machine (link).
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Old 11-04-2021, 01:26 AM   #7
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Quote:
Originally Posted by bobxyz;6227560

BTW: the original text from the first few posts of the DSM CAS Guide can still be found through the wayback machine ([URL="https://web.archive.org/web/20160304064651/http://forums.turbobricks.com/showthread.php?t=224740"
link[/URL]).
Thanks for the wayback info- I can see the text, but no images are available. Since the B20/30 distributors rotate counterclockwise, opposite to the OHC redblocks, it looks to me like the disc should be flipped opposite of the pic posted later in the thread. Will set it up this way and look at the composite logger once I am ready to install it.
Many thanks
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Old 11-04-2021, 11:47 AM   #8
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Also thanks for that wayback link, that was pretty helpful even without the pics!

Well, after much destroying of resistors, here is my progress and one question:

First, I tried setting up only the super simple tach circuit as described in 6.9.13 "Mitsubishi CAS with aftermarket disc" and did the mods in 5.2.3 "Hall Sensor Input". That includes a pull-up resistor on the board. That didn't work - I mean, I got action on the logger but it was all over the place even with different rising/falling options. I figure that I need to set up the Cam circuit too for this, even though I am going wasted spark. So much for the lazier option..

So now I am ready to do the mods in 5.2.14.2 "Adding a cam sensor input - hall sensor / optical sensor". After a bunch of reading, I am good with everything except I need one piece of advice: "a) JP1/pin3 should be connected with a jumper wire to a spare pin on the main DB37 connector (e.g. SPR3)". In my case SPR3 and SPR4 is used as spark A and B. I think that leaves me with two options - any advice on which is easier?

1 - Use pin 25 (IAC1A) since I will be doing PWM idle control later. Does anyone know if I have to disconnect anything else to use this pin?
2 - Use pin 36 (high current ignition) since I am doing wasted spark on pins 5/6. Does anyone know if I have to disconnect anything else to use this pin?

Thanks guys! I'll write all this up when done for the next person doing MS2/3.57.
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Old 11-04-2021, 07:50 PM   #9
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When the pictures first disappeared from the official DSM CAS Guide, but the text was still there, I wrote up this post and included the key pictures and related info: link. You need to be logged in to see the pictures. Once you're up and running, it would be great to add a couple B20 pictures to the Guide thread, specifically a picture of the disc in the CAS at TDC, and a screenshot of your MS Ignition setup.

For wiring, I think all 4 IAC pins on the DB-37 connector are unconnected and can be used for whatever you want. Take a look at the MS Hardware Guide section 13.4 jumper wires to make sure.
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Old 11-05-2021, 04:59 PM   #10
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Quote:
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When the pictures first disappeared from the official DSM CAS Guide, but the text was still there, I wrote up this post and included the key pictures and related info: link. You need to be logged in to see the pictures. Once you're up and running, it would be great to add a couple B20 pictures to the Guide thread, specifically a picture of the disc in the CAS at TDC, and a screenshot of your MS Ignition setup.

For wiring, I think all 4 IAC pins on the DB-37 connector are unconnected and can be used for whatever you want. Take a look at the MS Hardware Guide section 13.4 jumper wires to make sure.
Thanks so much - not sure how I missed your post in that thread. I'm taking pics as I go so should be able to produce something mildly helpful. Ordered some more resistors for that last step - and will be using one of the IAC pins on the DB37. Will need to de-solder one connection but that's easy to replace if ever needed.

Appreciate it!
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Old 11-11-2021, 01:48 PM   #11
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Thanks for all the advice. I am so close - actually, getting this CAS set up is the last step before firing my b20! But assuming I am reading the logs , I must have done something incorrectly or otherwise screwed some setting up. Any advice would be super appreciated. Hoping for any friendly Volvo advice before I jump into the MS forums...

I have the CAS wired as in bobxyz's excellent post, and am using the Yoshifab disc. I have done the mods in 5.2.3 for Tach and 5.2.14.2 for Cam. The Crank/Tach mod was easy. For the cam, I used the IAC1A plug on the DB37 connector (it was jumpered elsewhere to JS0, I removed and taped the jumper wire off). I also had to remove a jumper on JS10 (was jumpered to the middle pin of Q16) since the instructions were clear that nothing else should be on JS10.

The result is... not what I expected. Neither the tach signal nor cam signal (are they separate?) appear solid - they jump around a ton as if the pull-ups were not there (the pull-ups are there). The composite log when I removed the CAS and spun it by hand was similar to when it was on the engine. This is what it looks like by hand:



I went over all of my (admittedly, novice) soldering connections but they all appear to have continuity where they should, and the resistance is matching the pull-up resistor circuits:



The only customization on the back should the wasted spark jumpers:



And my settings in Tuner Studio:




What have I screwed up, I wonder? Any advice welcome!
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Old 11-11-2021, 02:36 PM   #12
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Try chucking it in a drill and spinning at a steady speed for a longer period of time.
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Old 11-11-2021, 03:06 PM   #13
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Try chucking it in a drill and spinning at a steady speed for a longer period of time.
That's a good idea - it is actually easier to just stick it back on the engine - cranking here without spark plugs installed, and no fuses except MS power and CAS power. Waiting to install the correct CAS plug until I get this working, hence the wire hanging out. And that green wire... don't worry about that green wire. It is a 5v+ with a resistor on it, to test that I wasn't just missing the pull-ups.

Wires here left to right are:
1. Ground wire that was shielded along with the shielding wire and white wire
2. 12+ power from fuse block
3. White wire that was shielded along with #1, which I believe is the outer tach signal
4. Blue/white wire which is the IAC1A wire that I re-purposed as the cam signal


Composite while cranking:


Tooth log while cranking:


Trigger log while cranking, blank?:


Thanks again for any guesses.
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Old 11-11-2021, 03:25 PM   #14
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While you are test cranking, at the CAS use a voltmeter connected between the cam output and ground to confirm that the cam signal is working. You should see the voltage transition from 5 volts to close to 0 volts and back to 5 volts as the cam window passes through the sensor module. If the signal is present at the sensor check at the MS box terminal to make sure that you don't have a 'field wiring' problem. If the cam signal is getting to the board I can't really help you with your board wiring as I am using the older through hole board and both my cam and tach inputs use opto isolator inputs which are ground switched by the CAS so no dedicated pull up resistors.
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Old 11-11-2021, 03:56 PM   #15
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While you are test cranking, at the CAS use a voltmeter connected between the cam output and ground to confirm that the cam signal is working. You should see the voltage transition from 5 volts to close to 0 volts and back to 5 volts as the cam window passes through the sensor module. If the signal is present at the sensor check at the MS box terminal to make sure that you don't have a 'field wiring' problem. If the cam signal is getting to the board I can't really help you with your board wiring as I am using the older through hole board and both my cam and tach inputs use opto isolator inputs which are ground switched by the CAS so no dedicated pull up resistors.
That's good advice, thanks. At the CAS, I am getting either .18v or 3.58v depending on where the inner wheel is. At the board (measured at JP1 pin3) I am getting either .17 or 3.51 depending on where the inner wheel is.

That seems like the wiring to the board at least is working, although I am assuming that 3.5v is "enough" to trigger. I followed the MS instructions which used a 470R resistor pull-up between a 5v and JP1 pin 3 - I wonder if I should swap it out with a 1k and see if that makes a difference in voltage?

Really appreciate the help - if indeed 3.5 is within spec, then I agree I may have a board wiring problem. At least the CAS wiring and the wiring to the board looks to be ok!
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Old 11-11-2021, 08:12 PM   #16
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Did you adjust the 2 pots (the little yellow things with a tiny brass flat-blade screw on the top) per the MS instructions? And, just to be sure, does +5Vref measure a steady +5volts on the TPS, or anywhere else it's connected to outside the MS box?

The 470 ohm pullup resistor on the cam circuit is OK, and the 3.5v is too.

[technical details: the 5.2.14.2 cam circuit uses the opto-isolator circuit, with one side of the LED grounded and the other side of the LED connected to the open-collector CAS pin, with a 470 ohm pullup. When the CAS isn't grounding the pin, the pullup turns on the opto LED, and the voltage on the CAS pin is the LED on voltage, plus a couple internal diode drops, so ~2.3v + .6 + .6 or ~3.5.]

Can you measure the voltage on the J1-1 wire (the output of the opto circuit) while turning by hand? This should swing ~0v to ~5v.
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Old 11-12-2021, 11:17 AM   #17
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I remember having trouble getting either the cam or crank trigger to function steady off the vr input and instead had to build a second opto circuit….
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Old 11-12-2021, 03:47 PM   #18
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Quote:
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Did you adjust the 2 pots (the little yellow things with a tiny brass flat-blade screw on the top) per the MS instructions? And, just to be sure, does +5Vref measure a steady +5volts on the TPS, or anywhere else it's connected to outside the MS box?
Yes - I spun the little pots as per the directions, and checked with the multimeter per the directions - showing 2.34v between R54 and ground.

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Can you measure the voltage on the J1-1 wire (the output of the opto circuit) while turning by hand? This should swing ~0v to ~5v.
Yes - the voltage between J1-1 and ground is either 4.90v (when the inner cam track is not through the hole) or .15v (when the inner cam track is through the hole). NOTE: this is measured by cranking the motor and then once at rest, looking at the stable voltage on the meter.

I also checked the tach circuit - it is showing 4.90v measured between R57 and ground. This also seems like the pull-up is doing its thing. NOTE: this is measured by cranking the motor and then once at rest, looking at the stable voltage on the meter.

After this troubleshooting, I had an idea - since it seems like everything is reading accurately at rest, perhaps the issue is voltage drop to the CAS when cranking? I measured the voltage between pins 1 and 2 on the CAS (that should be 12v and shielded ground) and got 12.15 when not cranking, but then it drops down to 10.8 when cranking. That seems like it might be enough to throw everything off, right?

Perhaps this 12v battery just needs a turn on the drip charger, and that since the voltage supplied to the CAS is dropping under cranking, the sensors are returning unreliable data. Is that... plausible? I chucked it on the drip... my carb'd volvo battery is not even quite showing 12v so that isn't a helpful quick swap.

In the back of my mind I remember somebody talking about an adjustment in Tuner Studio to teach the MS about varying battery voltages - is that a thing or did I hallucinate it?

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Originally Posted by cwdodson88 View Post
I remember having trouble getting either the cam or crank trigger to function steady off the vr input and instead had to build a second opto circuit….
Oof I hope not but I'd do whatever needed doing to make this thing run. Loving it.

Thanks for the continued advice, I really appreciate it. If it isn't this, my next guess is that it is the lack of shielding on the power wire going to the CAS... but voltage drop seems a more likely culprit.
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Old 11-12-2021, 04:32 PM   #19
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One more theory I will check: I went over all my power and grounding wires, and I notice that I assumed that the CAS should be grounded through the shielded wire that returns to the MS (pin 1). Seems like the MS usually just grounds sensors through itself, and those are usually at 5v max.

Other folks seem to have just grounded the CAS directly to the motor or back to the battery. I'll try that to and see if that makes a difference.

Just throwing stuff at the wall - something will stick .
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Old 11-12-2021, 08:45 PM   #20
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Your new measurements seem fine. And the battery dropping to ~10 volts during cranking shouldn't cause sensor problems (the MS, and the sensors, use a regulated 5.0volt supply, so they'll be OK with a battery voltage of ~7 volts or higher). The MS tables do include battery voltage compensation for injector/ignition timing at lower battery voltages.

Some folks have had problems using the MS2 VR sensor circuit for the CAS crank input, and have added a different circuit (either another opto-isolator or a Maxim chip like the one used in the MicroSquirt). I followed the same exact instructions as you're using, with power/ground setup per the MS hardware manual recommendations, and didn't have any problems. (The MS2 was also running low impedance peak/hold injectors without a resistor pack, but that took some non-standard mods to keep the noise down.) For an initial setup, you should be fine with the standard circuits. If you have timing drift problems after it's at least initially running, you could consider a different circuit.

The recommended MS power and ground wiring is shown here:
http://www.msextra.com/doc/pdf/html/...re-3.4-14.html

The key thing to notice is that none of the power or ground wires used by the sensors are shared with any of the high-current circuits. The high current circuits are the injectors, the ignition driver, the idle valve, the fuel pump, and the heater circuit on the O2 sensor. These all use separate +12v power wires/fuses off the fuel pump relay, and have a return ground path to the block through the MS box.

The sensors are all low current, and include the temperature sensors, TPS, CAS, and the O2 sensor signal. Sensor and MS power can be daisy chained from the main relay/fuse. The sensor grounds can be tied together where convenient but must go back to a dedicated sensor ground pin on the MS. For any sensors with shields, the ground wire and shield should be tied together close to the MS before going to the MS sensor ground pin.

Your tooth logs don't look like it, but can you check that your Ignition Settings -> Noise Filtering options are all OFF? Next, I'd try removing the CAS and rotating it by hand to eliminate any noise issues due to cranking. If the MS detects the CAS tooth pattern correctly, it will click on the fuel pump relay and start pulsing the injectors/ignition (if connected). You should be able to hear the fuel pump relay click on and off if your shop is quiet.
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Old 11-12-2021, 10:02 PM   #21
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The CAS ground carries DC power for the sensor in addition to the ground path for the cam and tach signal. Given that the sensor does not draw a lot of current, connecting the sensor ground to pin 1 is not a huge issue. When I did my set up, I ran the sensor ground directly to the common ground point on the motor. Since you are using the original B20 intake manifold there is a bolt on top of the manifold towards the back that was the common ground for the D jet system. That is what I used for the sensor ground and the ground connection for the controller (DB37 pins 15 - 19). If the CAS had a separate signal ground connection I would have run them to DB37 pin 1; but, it doesn't. Either option will work because the CAS sensor draws very little current and causes very little ground potential rise in the controller ground plane relative to the engine ground.

10.8 volts during cranking should be no problem for the CAS. I run a battery in the trunk in my 142 and the supply voltage during cranking drops to about 10.5 volts because of battery internal resistance and the long run from the trunk to the engine compartment. It has never presented a problem for the CAS.

Last edited by 142 guy; 11-12-2021 at 10:17 PM..
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Old 11-13-2021, 12:26 PM   #22
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Quote:
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Your tooth logs don't look like it, but can you check that your Ignition Settings -> Noise Filtering options are all OFF? Next, I'd try removing the CAS and rotating it by hand to eliminate any noise issues due to cranking. If the MS detects the CAS tooth pattern correctly, it will click on the fuel pump relay and start pulsing the injectors/ignition (if connected). You should be able to hear the fuel pump relay click on and off if your shop is quiet.
Checked and the noise filtering is off - thanks. Of course, I had to try turning it on temporarily and seeing if that made a difference - no dice.

I will triple check the wiring - my grounds are per the MS manual but I am running a single fuse block off the main relay that goes to MS, wideband, ignition, etc - not best practice and I'll correct that. The reason I think that isn't the issue here is because I have all the fuses pulled except MS and CAS up until this point except when I have been testing those systems separately.

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That makes good sense about the CAS grounding - and explains why when I tried a separate ground wire from the CAS to the manifold (thanks!) and when I tried a separate jumper wire from the battery to the CAS power it also did exactly nothing
Your posts did make me wonder if I was chasing my tail on looking for a tidy scope pattern on the composite logger. I found an article on the MS site about tuning the pots to adjust for noise filtering while cranking, and I fiddled about with those. Next, I took your advice and added the fuses back in for my injectors and spun the CAS by hand - I am definitely getting clicks from them and the corresponding LED light on the MS. I wonder if I should just go ahead, pop all the fuses in, connect the fuel, and try to fire the thing?

My sense from messing about on this is that the cam circuit is working, but the tach circuit is not. Not sure if that is correct, but the cam circuit is easy to test (since it is either ~0 or ~5 depending on the inner wheel) but the tach circuit just has the 24 teeth.

Do either of you guys (thanks again!) have any advice on testing the tach circuit either on the board or in software? Really appreciate your advice.
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Old 11-13-2021, 01:13 PM   #23
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Composite while cranking:
I don't know what's going on with the yellow lines -- maybe it's cranking too slowly and MS thinks there's a dropout?

I also don't know why the blue spikes are so erratic. I thought it was missing pulses, but I'm now wondering if it's OK and is just an artifact of the resolution in the High Speed Logger view. Can you zoom in on this screen and try again? If you zoom in, do you see evenly spaced blue pulses?

The red trace at the bottom of the screen is sync -- when MS correctly detects the CAS 12/1 pattern, it declares sync and drops the red signal. Assuming the blue spikes are actually OK, this screen shows that you have good sync for a brief period. The issue is that it goes back to bad sync just before the end of screen. Try changing your Ignition Input Capture to Falling Edge and see if it sync's up, and stays sync'd up better.

----
You can check the tach circuit with a multi meter and turning the CAS by hand -- 24 short pulses per rev versus 1 longer pulse per rev for the cam. Measure the voltage on J1 pin 2 or 4 or 6 (they're all tied together), and you should have a jumper pin 3 to 4.
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Old 11-13-2021, 02:02 PM   #24
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For my 3.0 version board, I bring the cam signal in to the processor via a jumper from OptOut to JS10. I recall that is the 'typical' arrangement. JS10 is connected to pin 17 on the 40 pin socket that the MS2 daughtercard plugs into. I bring the tach signal in to the processor via a jumper from VrOut to Tsel. Tsel is labeled IRQ-1 (or just IRQ on the daughterboard schematics) and connects to pin 14 on the 40 pin socket. Since you have the 3.57 board, I am not sure that the board is exactly the same, however, by looking at the schematics you should be able to confirm where your cam and tach signals are ending up on the 40 pin socket. I suspect that they will be pins 17 and 14 because I think the daughtercards are identical for the two boards.

Once you have confirmed the socket pin numbers on the 40 pin socket, remove the daughtercard from the 40 pin socket and power up the controller and the CAS with the CAS connected. It doesn't matter whether the CAS is in the engine or you are turning it by hand (I think by hand would be more convenient). Use your voltmeter to measure the voltage between pin 17 on the 40 pin socket and the MS board ground and then pin 14 on the 40 pin socket and the MS board ground while you rotate the CAS. You should see the voltage transition once per rotation of the sensor for the cam signal and 24 times per rotation for the tach signal. If you get those 0-5 volt (or 5 - 0 volt ) transitions at those pins and you have not somehow mixed the inputs then you know that the cam and tach input circuits are functioning and the signals are making it to the MS2 daughterboard.

I have never used the tooth logger during cranking so cannot advise whether the tooth logger will function reliably with a very low frequency or variable frequency signal (turning the crankshaft by hand).

You said that when you spun the CAS by hand you could hear the injector clicking. I suspect that those are cranking pulses on the injector that you are hearing and that suggest to me that both the cam and tach signals are functioning. It has been a long time since I looked at the firmware; but, my fuzzy memory is that with the Extra code nothing happens until MS2 gets the cam sync pulse and starts calculating RPM from tooth #1 on the tach wheel.

If you confirm that the tach and cam signals are working (or suspect they are working) you can move on to a cranking test on the engine using the starter motor. This time don't use the tooth logger. Look at the Tuner Studio dash display and pay attention to the RPM display and the Not Cranking and Not RPM synced flags. Those will give you an indication of what is happening.
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Old 11-13-2021, 02:55 PM   #25
floydilian
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Join Date: Dec 2019
Location: Sacramento, CA
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Thanks guys - I will try all those things this evening!

Meanwhile, figuring there is no harm in trying and guessing (hoping?) that as you both suggest, there might be unreliable outputs views in the logger, I've gone ahead and wired up my logic coil. I spun the CAS by hand and got spark on a plug wire and heard the clicks of the injectors. The LEDs on the MS are also blinking in line with the clicks.

So perhaps the MS is making sense of those cam/tach inputs after all - at least at this point I might as well give it a shot. This evening I'll reinstall the CAS onto the motor, and check for spark during cranking (starter is too damn loud to hear for injector pulses). Then I'll wire up the fuel pump and give 'er a shot.

... and then once that fails, I'll follow your suggestions for more troubleshooting

Thanks!
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