Blysccr

Put on ati and figured I’d “upgrade” to 36-2 trigger wheel.

rpm sync error:
miata 36-2
falling edge and rising edge tried both
errors 1 and 2
messed with the settings under it, forget the name of it but had 60-80 or 0-20
composite log is showing me anywhere from 26 to 38 “teeth”.

looked at some modifications with the megasquirt and haven’t found anything conclusive.

planning to just go back to oem style 4 tooth unless there is something stupid to get the FM 36-2 to work.

also flyin miata won’t sell a 4 tooth that fits ati damper. Well guess what, I will.

https://drive.google.com/drive/folde...G0aveQk2wIfSi0

Turbomack

Confirm the crank position sensor is 1 credit card thickness spacing from the trigger wheel before you give up on it. I don’t do megasquirt so can’t help you on that part but had some goofy readings at first tuning on a new build that fixed when I moved the sensor closer to the wheel.

Blysccr

I have a bigger write up on the Facebook group but seeing as it was getting no action I was hoping to get something here. I tried .005 .010 .015 and .020. Iirc .035 is oem setting but have read more reports of issues at that setting and tighter is better.

I can try oem and see what that leaves me with.

Reverant

iTrader: (10)

Change from Miata 36-2, to Generic Wheel, set number of teeth 36, number of missing teeth 2, wheel speed: crank. Set fueling to semisequential, ignition to wasted spark or wasted cops if you have sequential, disable knock per cylinder and VVT.

Crank and check if you now have sync.

DNMakinson

iTrader: (3)

This seems interesting. In to see where Reverant’s diagnosis process goes.

Blysccr

@Reverant will give that a shot when I get back home this week. Thanks!

Blysccr

Rev gave those updates a shot and i got a couple backfires. I changed the Tooth#1 angle from 80 to 270 for the logs. at 270 it seemed to crank easier but still no start. I'm getting less sync errors but still not getting a consistent 34 tooth counts.

Thanks!!


https://drive.google.com/drive/folde...i0?usp=sharing

Ted75zcar

iTrader: (2)

Is your tooth filter turned on?

Blysccr

I have VVT turned off. I'm thinking I need to do this as my Tooth #1 Angle

Ted75zcar

iTrader: (2)

no, the filters in the ign pull down under noise filter or something, I don't have a pc in front of me.

Blysccr

well with this new forum stuff i can't seem to upload pictures...

I think i need to use 180 degrees for Tooth #1 angle with the FM 36-2 wheel and stock miata sensor location

Blysccr

I think I know what you're saying, on the composite log during the latter cranks, the tooth count was on and had minimum read errors. I didn't try rising vs. falling and I think my #1 tooth angle is off but I was getting much cleaner signals. From what Ive read the filter is good if the spikes aren't uniform or youre getting a lot of mis read teeth. sorry can't post pics...

Ted75zcar

iTrader: (2)

No, there is a noise filter option in the ign pull down.

Blysccr

Everything is off on that...

Blysccr

Messed with this some more. Tried #1 angle with toothed wheel and miata 36-2 different angles on that. The car almost started a few times, but I think towards the end it was too flooded to matter. The "best" sounding setting was toothed wheel, rising edge, 270 Tooth #1 angle with noise filtering on and the oem settings for the filtering. 200 usec at 500 rpm.

https://drive.google.com/drive/folde...i0?usp=sharing

Blysccr

Ok so reviewing the logs, I saw 53 lost sync counts. Reason is still #2 I believe. Missing tooth at wrong time. Tried Tooth #1 angle everything between 0 and 360, sounded best around 270. To be sure, what is the best way to see what the current tune is at what MS shows 0 sync errors and the most consistent 34 tooth pulses? Also, i'm using Megalogviewer to check sync errors when cranking and some spots is very high- lots of errors when cranking, and other areas it's flat. SO that could be the right settign too, but not sure how to cross reference the current tune that resulted in that datalog.

Blysccr

also noticed on the composite log some times I have the green cam signal and other times I do not.

Reverant

iTrader: (10)

Is this an MS3X?

Blysccr

Ms3pnppro

Ted75zcar

iTrader: (2)

I recommend you stop ~trying stuff to see what happens~ and look at the raw composite logger data in a spreadsheet program. Tons of people are running FM36-2 wheels on MS3pros (myself included). Randomly changing settings in the tune is just shooting in the dark.

The MS manuals do a good job of explaining how you set a trigger wheel up. If your mechanical cam timing is good, then you can use CAM position at TDC to establish crank TDC and engine phase.

If stuff doesn't look right in terms of the missing tooth location, chances are you have a mechanical timing issue.

Ignore all the stuff people have out there WRT rising vs falling edge. That is a Boolean option that the uniformed love to play with because they think they know what they are doing. The modern MS variants use IC based trigger detection, so the slew rate differences between rising and falling edge has made this selection almost moot. For non-VVT applications, you simply need to select the option that places the cam trigger in a good spot on the crank trigger. You don't want the two triggers to overlap.

These settings do not vary across platforms much at all when using standard hardware. Any tunes that you can find out there that use the 36-2 from FW1.5 should get you in the ball-park. The 1.4 source code describes the implementation of the 36-2 miata triggers as well. If a standard setup doesn't work, confirm mechanical timing.

I don't see what motor you are using, be aware that an NA8 crank trigger sensor is not adequate for a 36-2 wheel. You need to use a BP4W sensor or newer. The BP4W sensor does not mount directly to a NA8 stock oil pump.


Edit:
/* ---------------------- Miata 36-2 99-05 --------------------*/
} else if (spkmode == 55) {
/* 36-2 on the crank with a 2/1 on the cam */
unsigned int i;
cycle_deg = 7200;
flagbyte5 |= FLAGBYTE5_CAM;
no_teeth = 68;
last_tooth = no_teeth;
for (i = 0 ; i < 68 ; i++) {
deg_per_tooth = 100;
}
deg_per_tooth[33] = 300;
deg_per_tooth[67] = 300;

smallest_tooth_crk = 100;
smallest_tooth_cam = 900;

no_triggers = 4;
trigger_teeth[0] = 19;
trigger_teeth[1] = 35;
trigger_teeth[2] = 53;
trigger_teeth[3] = 1;

trig_angs[0] = -300 + tmp_offset;
trig_angs[1] = -300 + tmp_offset;
trig_angs[2] = -300 + tmp_offset;
trig_angs[3] = -300 + tmp_offset;

if (num_cyl != 4) {
conf_err = 1;
}