loosing sync
Turbo Mini Forums

what do you guys make of this, engine runs beautifully but every now and again there is a misfire that is caused by ms loosing sync, never really managed to get decent logs of it but yesterday i got about 3 hours play time and have found these

i have tryed alot of things, but interestingly the rpm are very very close making me think it is possibly a vibration problem or some electrical noise




bloody png's work but not jpg's lol

Edited by Brett on 11th Mar, 2012.

Yes i moved to the darkside

Instagram @jdm_brett

and as typical pictures wont upload :(

png's to the rescue

Attachments:

145.99kb

156.93kb

Edited by Brett on 11th Mar, 2012.

Yes i moved to the darkside

Instagram @jdm_brett

I don't know if you have a VR sensor but if so, have you tried adjusting the trim pots?

Jean

http://www.jbperf.com/

it is a VR sensor, i have done some tweaking with the trim pots but could not really notice any difference

Yes i moved to the darkside

Instagram @jdm_brett

Reason 2 (as shown on your log) is usually a missing tooth error.

The other logs would seem to confirm it.

Many possibilities.

Vibration (moving gap) of the sensor quite possible.

Noise (at higher RPMs) also quite possible.

What about the VR pot positions - the standard VR input circuit really is crap - maybe just a small tweek of the pots, especially the lower one, would help clear it.

The VR voltage rises with RPM so maybe your gap is actually too small.

Also, double check the polarity of the VR sensor and your ignition input (rising/falling) setting.

Best I can think of at the moment.

Schrödinger's cat - so which one am I ???

cheers so far guys, Rod i have had my sensor bracket off and modified it, the sensor is now a whisker away from the wheel as i thought it was not close enough
things on the to do list,
-change the shielded cable as its the std one from diy, and is single core and sheild
-another different VR sensor
-another fiddle on the VR Pots
-try a much larger sensor-wheel gap
-the capacitor mod on the coil pack i have never used it but worth a try

Yes i moved to the darkside

Instagram @jdm_brett

try moving it away a bit, iirc if the wheel touches the vr sensor it can cause this.

as youve had it running before and the only thing youve changed is the bracket? it must be that I reckon.

always had the odd misfire, i found this lost sync issue by accident it used to be really bad at starting also caused by a lost sync.
The starting issue is much better now its closer but the one in the logs above is still here, i will be able to see if its just touched the wheel i will have a look in the week

Yes i moved to the darkside

Instagram @jdm_brett

personally I'm a fan of hall sensors rather than the VR, you can wire them pretty much straigt into the opto isolator input bypassing all the pot stuff.

does mean you have to ditch the edis though

edis never even got a look in here

is there an equivalent hall sensor to replace the VR still using the 36-1 wheel?

Yes i moved to the darkside

Instagram @jdm_brett

how about one of these.

http://www.diyautotune.com/catalog/hall-ef...nsor-p-489.html

http://www.diyautotune.com/catalog/hall-ef...nsor-p-479.html

I'm using the M12 hall sensor on both my new 998 turbo builds. I use the same sensor for cam and VSS signals as well.

Interesting that DIYA just connect it up to the VR circuit.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

hmmm interesting i may have to switch to one of those in the near future

Yes i moved to the darkside

Instagram @jdm_brett

The opto circuit can be problematic with high-tooth count wheels if you use the standard components due to filtering and the opto-coupler response. This is not an issue with the VR circuit (but there are other issues).

You can also use a MAX9926-based VR conditioner (such as my dual VR board V2.0) which has been proven to be better in a lot of cases.

Of course this assumes that the mechanical and EMI issues are taken care of independently.

Jean

http://www.jbperf.com/

Yes i moved to the darkside

Instagram @jdm_brett

are you using the MS to controll boost?

not yet but every thing is there for it

Yes i moved to the darkside

Instagram @jdm_brett

ok I was just wondering if the MS was throwing a spaz and bleeding off all the boost signal,

dump valve and actuator feed from the same place? i'd keep them seperate.

actuator feed from turbo compressor, dumpvalve from plendemlebob

the actuator feed is about 2m long though as it comes inside to a bleed valve, i would have thought it would make the boost spikey at gear changes but not cause boost creep - what would you say?


the 2nd Screenshot shows it go very lean, it looks like ages have past by the logs but i lifted as soon as i saw it, or benny called it whichever lol
not bad on a needle i polished up last night with no testing i think i need to retry the 12lb spring though the needle seems to be at the top before it finishes revving

Attachments:

119.56kb

122.71kb

126.28kb

Edited by Brett on 12th Mar, 2012.

Yes i moved to the darkside

Instagram @jdm_brett

could just be a kink in the pipe or somthing,

link the bleed valve out and see what its like. then link the compressor to the actuator with a short pipe to chek thats ok

I used to use a in car bleed valve and that gave the same problem as you are describing. You cold try a under bonnet valve or tube with holes drilled to test?

ill have a fiddle with that then cheers :)

Yes i moved to the darkside

Instagram @jdm_brett

I've had the same. The pipe was pinched.

In the 13's at last!.. Just

ill drag this back up as it all seems relevant :)

Yes i moved to the darkside

Instagram @jdm_brett

have you paid for the full tunerstudio?

then under diagnostics select tooth logger and hit start.