MS3 configuration for 60-2 + "cam sensor"

[westco4k]

so I finally got everything installed and wired in yesterday for my crank trigger hall sensor and a one window distributor being used as a cam sensor. I removed/changed the components and added jumpers as described here http://msextra.com/doc/general/tachin-v30.html#spareopto thanks to DE80q for the help on finding that info. and I configured MS as best as I could from what little 5cyl info I could find in the manual/here/and MSextra stuff.
Now I am not seeing an RPM signal in megasquirt and I am relatively certain it has something to do with my configuration. I thought maybe if I posted a couple pics here someone might see a red flag in my setup. my crank signal seems to be getting thru according to the tooth logger but I still don't see any tach signal.



when I found this write up: http://forums.turbobricks.com/showthread.php?t=126892

I noticed he said to describe it as a 120 tooth wheel but never touched on why or if I needed to then tell ms it is a cam wheel or if it was now 4 missing teeth. . . but once again its all old ms1 extra stuff and not easy to tell if it translates well into ms3

here is my ignition configuration, I have tried describing it as both a single wheel with missing teeth and a dual wheel missing teeth but I haven't tried the 120 tooth thing yet.



just not sure what to try next and im not really sure how to tell if the cam signal is getting in at all. I sent the signal for it to IAC 2A since it wasn't being used. jumpered that to XG1 like the schematic says for the secondary cam sensor input. the only other thing I can think of, since mine is a 3.57 some of the 3.0 mod instructions are a little unclear. I jumpered JS2 which I believe to be optoout to JS10. . . could that be my mistake? wrong opto out maybe?

[westco4k]

so I found out the ecu mod is different on a 3.0 vs 3.57 but I have already got that all straightened out. now to see if the cam sensor signal is getting thru.

[vt10vt]

A 60-2 wheel is technically read as a 120/rev wheel relative to the cam sensor. Crank speed = 2x cam speed so the 60-2 will rotate twice for every time the ECU sees a cam pulse.

It's not really relevant any more, the software does the calculations but on the older MS1 wheel decoder stuff you had to tell it how many teeth to count to get to "X" angle and so you had to count in 120 teeth especially on a 5cyl since you can't run wasted spark. On a wasted spark setup obviously it doesn't matter which cam sync you're on, but technically a 4cyl on COP on that old software would need a 120 tooth count. Largely irrelevant, your settings all look "right enough" to get an RPM signal even if it isn't really right.

Get your cam signal working well, you can pull the top of the ECU case and pull a signal straight off the CPU pin being careful not to short it to adjacent hardware. Just like testing a distributor, either crank or spin the dizzy by hand and watch for voltage swings. If it's happening at the CPU pin you know the rest of your circuits leading up to it are working.

[elaw]

It sounds like your cam signal is not making it to the processor. But to be sure what you need to do is take a composite log. Do that, get a photo, and post it here (and/or post the log file itself).

[westco4k]

So I got the ecu back in last night and did a composite log. Still not getting any signal from the distributor but the sync loss seems to mimic the crank signal. . . Gonna check my hall connection and move my coil a little since the harness runs right by it.

[elaw]

Can you describe the entire signal path from cam sensor to processor? I have a funny feeling there might be a "missing link" there somewhere.

Re the coil, keeping wiring away from it is an excellent idea, but that's probably not the origin of this problem. If MS is not getting an RPM signal it won't be energizing the coil, so the coil can't be creating interference.

[westco4k]

good point about the coil. I was getting a wonkey tach when running on the distributor but never a jumpy signal on the ms side. I may just move it anyway later

as for my signal path I cant say I know the circuit board like a map but I did follow the right instructions this time. according to MS3base/3.57hardware manual without expansion, 5.2.14.3 it goes - green hall wire - IAC2A in the diy harness - IAC2A on the main board jumpered to JP1 pin 3 - J1 pin 1 jumper to JS10 - jumper XG1 to XG2 - changed R12 to 470R and removed C30.

my distributor is pulling power from vref just like the rest of the sensors that are all working. ground goes to the upper bell housing bolt where most of MS is grounded.

[westco4k]

I checked a few things today, good power and ground at the sensor, good continuity on the signal wire from the sensor to the db37. I even switched from using IAC2A to SPR4 just incase that was a bad input to use. still no signal. the only other thought I had was do I need to jumper from the spr4 pad on the board to the pin itself? seems un needed but I have been wrong before

[westco4k]

here is my composite log with jumper JP1-JP2 installed


and here is a composite log with jumper JP2-JP3 installed out of curiosity


seems like the signal is getting from the sensor to JP3 atleast. . . the question is what am I missing?

[elaw]

here is my composite log with jumper JP1-JP2 installed


and here is a composite log with jumper JP2-JP3 installed out of curiosity


seems like the signal is getting from the sensor to JP3 atleast. . . the question is what am I missing?

Do you mean jumpering pins 1-2 on JP1 vs. pins 2-3?

If I understand this setup properly, you want to jump pins 1-2 only and leave it that way. Basically JP1 is designed to allow selection of one of two trigger input circuits, but this setup actually uses both. The crank trigger goes through the VR circuit (consisting of U7 etc.) via JP1 pin 1. But you're also using the "opto" circuit which is U3 and associated components, for the cam. Jumpering JP1 pins 2-3 sends the crank signal through the opto as well as the cam which definitely will not work.

It seems like you might be missing a pullup resistor for the cam input... did you follow steps e-g of the instructions on page 70? That's the pullup resistor, without which the cam sensor will not work.

[westco4k]

yeah I tried the +5/pullup after waiting without much reply and it fired right up. figures I read this after the fact lol. but for some dumb reason I thought the bosch was a 0-5v signal not a switch to ground. just glad its running again. much better than it ever did off of the distributor alone. it actually makes boost and pulls pretty well, haven't taken it above 4k yet and im still running the 7.5lb wastegate spring but its running much better now. thanks to everyone who has helped me get this car running twice now. this 5 cyl megasquirt journey has been a steep learning curve but I know how rewarding it will be.

here is my composite log when it fired first try after the pullup was added.