CEL MS3 Basic Sync Loss
 

I'm getting a sync error (CEL 8) and I'm trying to pinpoint the cause. I'm thinking it looks like a crank sensor based off of the log. does anyone see anything different?

Lost sync reason = 2, missing tooth at wrong time. A composite log would tell us more, but I believe that does point to a crank sensor issue. Double check sensor gap.

So I haven't been able sort this out yet but I was finally able to get a composite log showing the issue. Since I first posted this thread I have replaced the crank and cam sensors with new factory ones. and played with the gap on the crank sensor ranging from .035" or .889MM to .020" or .508MM with it making no difference from one setting to the other. (This log with the smaller gap) Trigger wheel is a FM 36-2

The issue is happening randomly between 7000RPMs - 7800RPMs (Redline) and feels like I'm hitting a brick wall! This became a really big problem last month when I tried to run a trackday and was basically losing 1000RPMs worth of each gear. I was having to shift super early either coming out of corners or having to shift up again right before braking zones only to shift right back down again because I could no longer hold the gear like I used to.

It seams odd that I would have burned though a new crank sensor so fast but I'm at a loss for what it could be.

Here are some screen shots showing the area where the issue happens on both files.
https://cimg3.ibsrv.net/gimg/www.mia...30a1a204d4.png
https://cimg4.ibsrv.net/gimg/www.mia...fbc198c22a.png

Is is possible to capture it in more logs? I would like to see if this always happens at the same time or it happens at a random tooth every time.

The sync loss happened a few times on this log. Do these screenshots help or are more .csv files preferred?

https://cimg4.ibsrv.net/gimg/www.mia...d2b4af4538.png
https://cimg5.ibsrv.net/gimg/www.mia...19e70a77df.png

Send me your current tune whenever you can and I'll have a look.

I just sent it via email. Thanks for taking a look.

Switch to falling edge on the input capture, that's what I have on my car. Also, switch the dwell to 3ms and spark duration to 1ms.

Reverant: and you run no filtering, correct? I have had good success running a filtering scheme, but would rather not need to.

OP: If you switch from rising to falling, you may wish to recheck the base timing. I’m not sure how many degrees wide the tabs are.

I have the "Noise Filter Enabled" set to "On" in my car. All other filters off.

Update: I made the changes listed below and was having issues getting the timing set when I switched to falling edge. It seemed like I kept getting timing drift. The drift only seemed to be with falling edge.

I tried to set it where most of the flashes on the timing light hit the right spot hit the drift was bad. I then used the FM digital angle finder to try and find the difference in degrees from the front side of a trigger wheel tooth to the back side and got a 5° difference so I adjusted the setting from -2° to 3° (probably not the best answer but I gave it a shot) The car was VERY unhappy with this setup and I only made it a few minutes down the road towards my "tuning" area before I had to revert the settings back to rising edge in order to make it back home.

Unfortunately I had to leave on the 21st for a training exercise and won't be back to the car until the 1st of August.

Do you know if there is another setting I need to adjust when going to falling edge? I saw the note in the settings saying the the setting needs to match the "tach input" I believe. But couldn't find a clear adjustable setting for this.