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-   -   MS3 na cas sync problem? (https://www.miataturbo.net/megasquirt-18/ms3-na-cas-sync-problem-53603/)

ianferrell 11-23-2010 10:19 AM

Bumped the dwell up to 6ms cranking and no dice, switched connectors (swapped A+B outputs) No dice, still ran fine on oe ecu. Checked my harness (again) to verify pin 14 and pin 33 (beeped w/ my multimeter). Didn't quite have time to mess with trying other spark outputs, I'll do that tonight. Really feels like bad spark outputs on the ms3x, i haven't moved the pins at all previously so I can't see how it'd be anything I did. Really wanted to get tuning time in before the weekend because I've finally got a chance to pull the motor and getting ready for turbo, if this thing has to go back to GA I don't think theres anyway I'll have time to make it work.

(BTW, ppl run 3.5ms cranking with these toyota COPs, 2.5 running... But they also run fine on the stock ecu's so I was pretty sure 6 wasn't going to help it but wasn't going to hurt either)

Braineack 11-23-2010 10:23 AM

BTW, MS-III is looking for the value at 13.2v, not 12v.

I use 5ms cranking and 2.1ms running.

ianferrell 11-23-2010 10:31 AM

Ah, I noticed the curve didn't match up to 12v = 100% dwell... figured it wasn't a big deal though.

Ben 11-23-2010 11:05 AM

I can't see how you would have 2, let alone 4, bad spark outputs.

This would be a great occasion for an oscilloscope. Or you could even use a JimStim and jump the spark outputs to IGN LEDs on the stim.

ianferrell 11-23-2010 11:53 AM

jmscortina did just that and was getting spark output with my exact msq. I don't have a jimstim or an o-scope, though I could make arrangements, what would either tell me that we don't already know? I agree its unlikely but I feel like I've ruled everything out. I mean, if it worked on the bench that still doesn't make my car go :)

My thread on msextra.com last post is where James tested it for me.

muythaibxr 11-23-2010 03:06 PM

It could be used to tell if the outputs are broken or the coils you're using just need to be driven differently.

I'm using toyota 1zz-fe COPs on my 20v 4age and they work fine, but I'm driving them one coil per output.

Ken

Ben 11-23-2010 03:16 PM


Originally Posted by Ben (Post 660405)
Continuity test the big ribbon cable if nothing else pans out. Those ribbon cables are machine assembled, not hand assembled, so I don't think there's a problem there, but ya never know...

Bumping my own post here because I didn't know if you tried this yet.

The very first MS3X ribbon cable that we hand made here didn't have continuity on a couple of the spark outputs. It looked fine, but a couple of coils failed to fire. A quick test with the DMM condemned the ribbon cable.

Now all the cables are machine produced, and should be totally fine, but can't hurt to check.



http://www.msextra.com/doc/ms3/pix/ms3-jp2.png

ianferrell 11-23-2010 03:48 PM

Guess I'll check the ribbon cable when I get home. I don't know that anyone else is in fact driving them wasted spark from the MS3x, though I think Braineack ran them that way for a little while... I guess I can also disconnect the plug from coil 4 and see if 1 starts sparking.

Braineack 11-23-2010 04:08 PM

um wasted spark i was driving through main board. seq spark through ms3x. but Ive tested wasted spark through ms3x cause the output test mode is fun.

ianferrell 11-23-2010 04:14 PM

So you drive 2 toyota cops off ms3x spark A on the bench and they both fired no problem?

Braineack 11-23-2010 04:31 PM

I believe I have, yes. I can't remember what I tested, but I was sure I tried wasted when figuring out how I messed up my wiring with I first went seq.

there would really be no reasons why one would spark and the other not, it's just a trigger for the coil to release its load.

muythaibxr 11-23-2010 04:35 PM

I've only driven 1 at a time per output myself. If 2 together draw more than 25 mA it may not work. Also, when we originally got the first ms3x boards about a year ago, we had to change the resistors on the outputs from 1k to whatever they are now (the value escapes me) because the Toyota COPs seemed to want a pretty strong 5v to trigger. Putting 2 on one output may itself be causing the problem.

you may want to try unhooking one of the coils from the output and then try test mode to see if the remaining coil sparks.

Ken

ianferrell 11-23-2010 04:36 PM


Originally Posted by Braineack (Post 661038)
I believe I have, yes. I can't remember what I tested, but I was sure I tried wasted when figuring out how I messed up my wiring with I first went seq.

there would really be no reasons why one would spark and the other not, it's just a trigger for the coil to release its load.

I wouldn't think so either, but after Ken's comment I'm thinking its possible the spark outputs don't have enough nuts to trigger 2 coils. I hadn't even considered that a possibility as lame as that would be.

ianferrell 11-23-2010 11:15 PM

Turns out the ms3x cannot push enough current to drive 2 toyota coils from the same spark pin... All A B C and D are working fine, I'm thinking I'm going to steal the wires from the EGR solenoids to use as the other two triggers. No sense in running new ones when there are perfectly good wires already there :)

Braineack 11-24-2010 08:34 AM

well that's lame.

muythaibxr 11-24-2010 10:27 PM

They supply 25 mA. The inline resistors there may be cutting things below what 2 coils need compared to 1.

You could jumper them but then if the two coils together are more than 25 mA you'd fry the chip.

We put 8 drivers on the board and supply the "wasted COP" output mode for this very reason though. Each output is designed for 1 coil. The same as the injector outputs. Each one is designed for 1 injector.

Ken

ianferrell 11-25-2010 12:12 AM

You wouldn't want to drive 2 coils on two ports from one wire tho would you? To me you wouldn't ever run wasted COP unless you didn't have cam sync or you only had one wire running to the coil triggers.

BTW, tested using the EGR solenoid wires (purge and vent iirc), got all 4 spark'n in order... and it started, I'm gonna sleep well tonight :)

ianferrell 11-25-2010 12:26 AM

Weird thing tho, started showing 18,900-29,800 rpm when I turned the ms on, showed sync and spark cut... figured 'what the hell' and did the spark test anyway, wasn't paying attention but it dropped back to 0 rpm at some point... When I tried to start it I didn't have the laptop hooked up (last minute, 'why not' moment. beer induced no doubt) and it clearly was reading the appropriate rpm at that point, idled right away. Any ideas what would cause that? Previously its only ever showed 0 at boot up, and it wasn't oscillating like it was an error, just a steady bizarre reading.

muythaibxr 11-25-2010 08:05 AM

Wasted COP was originally intended for those who have COP but no cam sync. We never intended for anyone to have an output hooked to more than one coil.

Ken

ianferrell 12-07-2010 11:53 AM

Back to having a sync issue, now when the CLT is up to 150+ it loses sync at idle, reliably does great up till this point... smooth, (tho my idle valve isn't working, dialed the screw out a little so it'll idle around 1000) It'll be running along fine and then shows an rpm spike and stutters and increments sync loss, it seems 'fairly' random, but happens enough that it will eventually die, as it'll have errors sometimes while its recovering from the previous error.
I'm going to pull the caps back off the abe fm circuit and see if it doesn't get any better. If that fails or it gets worse I may just say screw it and pull the motor to start preparing for the turbo... If its actually my cas (which I doubt) I have a spare from a 1.6 but will prolly just setup the trackspeed wheel and tune it from there, it idles well enough now.


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