Unexpected Missing tooth

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driftkids
Posts:18
Joined:Sat Jun 25, 2016 7:43 pm
Unexpected Missing tooth

Post by driftkids » Sat Jul 08, 2017 7:48 pm

Struggling with my S54B32

in the dyno a few days ago it started to cut at 5700rpm

we found out it had Unexpected missing tooth error at 3500-3700 rpm

tried different settings on trigger and best result were

Adaptive threshold: LOW
Pullup/Pulldown: None
Input Filter: None

and Crank detection scale 70%

with these settings the unexpected missing tooth error appeared at around 4500rpm

I also added 1K ohm at the VR sensor signalwire, that raised the unexpected missing tooth error to 5500 rpm, and the car revs up to 6500rpm.

Does anyone have had a similiar situation or have any suggestions here?

Karel
Posts:408
Joined:Wed Sep 10, 2014 11:58 am
Location:Czech Republic
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Re: Unexpected Missing tooth

Post by Karel » Sat Jul 08, 2017 7:55 pm

you are for sure using stock wiring huh ?

use high quality shielded twisted cable for cam and crank sensors and you will be fine without any resistors.

stock wiring sucks

driftkids
Posts:18
Joined:Sat Jun 25, 2016 7:43 pm

Re: Unexpected Missing tooth

Post by driftkids » Sun Jul 09, 2017 10:40 am

Its not stock wiring, i built a standalone harness


Im usibg raychem shielded wire on the crankv(vr sensor)
On the camsafts sensora (hall) i dont use shielded

gregpe
Posts:204
Joined:Sun Sep 28, 2014 12:19 pm
Location:Cambridge, UK

Re: Unexpected Missing tooth

Post by gregpe » Sun Jul 09, 2017 1:04 pm

10k resistor in series in primary trigger will do the job.

RHD
Posts:537
Joined:Tue Oct 07, 2014 4:28 pm

Re: Unexpected Missing tooth

Post by RHD » Mon Jul 10, 2017 4:06 pm

try using "next edge rejection angle" filter you will not be able to go any higher than 5 and even that might make it hard to start but try lower value, that usually does the trick too.

driftkids
Posts:18
Joined:Sat Jun 25, 2016 7:43 pm

Re: Unexpected Missing tooth

Post by driftkids » Mon Jul 10, 2017 10:12 pm

tried changing rejection angle, on 1,2,3 it was the same as before, on 4 and 5 it randomly stopped and was giving prime trigger noise error

will test with 10k ohm in serial tomorrow, if no other settings could do the trick ?

Karel
Posts:408
Joined:Wed Sep 10, 2014 11:58 am
Location:Czech Republic
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Re: Unexpected Missing tooth

Post by Karel » Tue Jul 11, 2017 7:29 am

I am really curious why do you play with setting, resistor etc.... you have everything right, only your wiring is shit, so change the cable for this sensor and done

driftkids
Posts:18
Joined:Sat Jun 25, 2016 7:43 pm

Re: Unexpected Missing tooth

Post by driftkids » Wed Jul 12, 2017 9:45 pm

Karel wrote:
Tue Jul 11, 2017 7:29 am
I am really curious why do you play with setting, resistor etc.... you have everything right, only your wiring is shit, so change the cable for this sensor and done
changed my "shitty wiring" with brand new shielded cables.. all the same

added after that a 5.6k ohm resistor on the triggersignal wire. it now rev`s like a wild cat! :D

Karel
Posts:408
Joined:Wed Sep 10, 2014 11:58 am
Location:Czech Republic
Contact:

Re: Unexpected Missing tooth

Post by Karel » Thu Jul 13, 2017 8:35 am

funny, i really dont need any resistors if the wirring is high quality... but anyway glad to see you are fine now

driftkids
Posts:18
Joined:Sat Jun 25, 2016 7:43 pm

Re: Unexpected Missing tooth

Post by driftkids » Thu Jul 13, 2017 11:18 am

I have heard from more people that they need to install resistors on the s54 engines to get the trigger working properly.

Also for guys running maxxecu aswell

WHPZach
Posts:184
Joined:Tue Oct 07, 2014 11:13 pm

Re: Unexpected Missing tooth

Post by WHPZach » Thu Jul 13, 2017 10:15 pm

Karel wrote:
Thu Jul 13, 2017 8:35 am
funny, i really dont need any resistors if the wirring is high quality... but anyway glad to see you are fine now
Resistors are needed on some signals, even with high quality shielded wire. With a VR sensor, the voltage output at high rpm can exceed what the EMU/EMU Black is capable of reading.

gregpe
Posts:204
Joined:Sun Sep 28, 2014 12:19 pm
Location:Cambridge, UK

Re: Unexpected Missing tooth

Post by gregpe » Fri Jul 14, 2017 1:55 pm

driftkids wrote:
Wed Jul 12, 2017 9:45 pm
Karel wrote:
Tue Jul 11, 2017 7:29 am
I am really curious why do you play with setting, resistor etc.... you have everything right, only your wiring is shit, so change the cable for this sensor and done
changed my "shitty wiring" with brand new shielded cables.. all the same

added after that a 5.6k ohm resistor on the triggersignal wire. it now rev`s like a wild cat! :D
thats what i've suspected..:)

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