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Unexpected Missing tooth
Posted: Sat Jul 08, 2017 7:48 pm
by driftkids
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?
Re: Unexpected Missing tooth
Posted: Sat Jul 08, 2017 7:55 pm
by Karel
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
Re: Unexpected Missing tooth
Posted: Sun Jul 09, 2017 10:40 am
by driftkids
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
Re: Unexpected Missing tooth
Posted: Sun Jul 09, 2017 1:04 pm
by gregpe
10k resistor in series in primary trigger will do the job.
Re: Unexpected Missing tooth
Posted: Mon Jul 10, 2017 4:06 pm
by RHD
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.
Re: Unexpected Missing tooth
Posted: Mon Jul 10, 2017 10:12 pm
by driftkids
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 ?
Re: Unexpected Missing tooth
Posted: Tue Jul 11, 2017 7:29 am
by Karel
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
Re: Unexpected Missing tooth
Posted: Wed Jul 12, 2017 9:45 pm
by driftkids
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!

Re: Unexpected Missing tooth
Posted: Thu Jul 13, 2017 8:35 am
by Karel
funny, i really dont need any resistors if the wirring is high quality... but anyway glad to see you are fine now
Re: Unexpected Missing tooth
Posted: Thu Jul 13, 2017 11:18 am
by driftkids
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
Re: Unexpected Missing tooth
Posted: Thu Jul 13, 2017 10:15 pm
by WHPZach
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.
Re: Unexpected Missing tooth
Posted: Fri Jul 14, 2017 1:55 pm
by gregpe
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!
thats what i've suspected..
