VR Erratic readings, setup questions...

[Reini1977]

Hi all..

Have some headaches and frustration setting up a Genboard V3.8 with the latest Firmware on a Formula Car..

engine is a 4 cylinder 2.0

trigger wheel is a 4 tooth in equal spacing, one tooth on the cam, all with VR sensors, ignition is 4 x COP

observations: when i set the primary trigger to 4cyl_C004_camsync, the engine starts so-so but rpm reading is double that what it actually is. also "fields" in the status bar starts to flicker around, as some other gauges, so e.g. IAC flickers on off, altough IAC is disabled, engine runs with ITB, so no IAC at all...


my questions:
do you have an idea, how to get rid of the erratic readings?

should i upgrade to another trigger wheel?

any help would be greatly appreciated!!

thank you

[Kamuto]

Hi all..

Have some headaches and frustration setting up a Genboard V3.8 with the latest Firmware on a Formula Car..

engine is a 4 cylinder 2.0

trigger wheel is a 4 tooth in equal spacing, one tooth on the cam, all with VR sensors, ignition is 4 x COP

observations: when i set the primary trigger to 4cyl_C004_camsync, the engine starts so-so but rpm reading is double that what it actually is. also "fields" in the status bar starts to flicker around, as some other gauges, so e.g. IAC flickers on off, altough IAC is disabled, engine runs with ITB, so no IAC at all...


my questions:
do you have an idea, how to get rid of the erratic readings?

should i upgrade to another trigger wheel?

any help would be greatly appreciated!!

thank you

your trigger reference table is bad I believe, or some other point of config is wrong, place log here and configuration, but anyway, I would recommend  upgrade to trigger wheel who has missing tooth, like 36-1 or similar, 4 tooth can cause you some problems later I believe

[Reini1977]

Hi and thank you!

unfortunately i cannot post the log now, the car is at my home 80km away...but will do ASAP!

i have checked x times and im sure i have no mistake in it...

in the trigger menu...Number of teeth of full engine cycle...so, a full cycle is 720° therefore 8 teeth..maybe another option i should look for?

Best thing, you are right, is to choose a missing tooth trigger wheel

do you have an idea what the flickering causes? grounds are in heavy wire direct to the engine block, maybe i should use a capacitor before the VEMS in V+?

regards

[Reini1977]

hi, Update!

made a trigger log, events look good, everything is where it should be..what i noticed, once in the log, a full enginecylce the ignition was off, then it worked flawless again.

another thing, when i set the TDC after trigger to 0, the eninge starts and run....but with 0 advance, the vems cannot calculate...!

i will get rid of the 4 tooth wheel and go with 36-1...

another thing, is it normal that IAC status comes on, when usig the IAC output for ignition?

thank you!

[wersch]

There is no dedicated output for the IAC valve, all outputs are versatile.
Even if IAC is not connected the indication event comes on so no problem there  :)

[Kamuto]

hi, Update!

made a trigger log, events look good, everything is where it should be..what i noticed, once in the log, a full enginecylce the ignition was off, then it worked flawless again.

another thing, when i set the TDC after trigger to 0, the eninge starts and run....but with 0 advance, the vems cannot calculate...!

i will get rid of the 4 tooth wheel and go with 36-1...
put some logs here would be interesting to see what's there

another thing, is it normal that IAC status comes on, when usig the IAC output for ignition?

thank you!

[Reini1977]

Hi all!

what i meant with IAC flag is, i use the stepper motor outputs for ignition...when the engine is starting, IAC flag is coming on..is that normal?

next thing, that gives me big time trouble is..

i installed a 36-1 trigger wheel today with a tooth spacing of around 7mm (tooth 4 mm. space 7mm)
When i start without the plugs (no compression) i get a nice wave (like a pic in the education books for electronics) from the crank VR  on the scope and all 4 plugs fire...

When i start with the plugs, i get trigger errors and no spark/injector signal, i assume du to the high compression

the engine have around 18:1 compression, thats "normal" for Formula 3 cars, i was told

also tried different filter settings, still trigger errors (tooth  and no start ( can see in the trigger log, that VEMS doesnt switch on the coils)

can you point me in a direction, setup, different trigger wheel, firmware etc?  im a bit lost right now....

thank you

[wersch]

The IAC flag is normal, you can asign any output for the IAC not just the stepper OP.

Do you have resistor spark plugs? If not you can get big problems there.

[Reini1977]

Hi Wersch

i have a COP system with the VAG coils, when i put the plugs in the COP assembly (plugs not in the engine, no compression) i get a stable trigger and a nice stable spark.
no errors and no interferences....

As soon as i have compression, i have trigger error and no spark...

[fphil]

ngine have around 18:1 compression

I believe Vems may put an error if the difference of the time period between 2 trigger events is too large. This may occur if the compression is really high.
There have been a post about it. I do not know the solution except the whislist. Indeed some systems offers the user  to parametrize the thresholds which trigger the errors and alarms.

[Reini1977]

hi fphil!

would it be better to switch over to a coil tcpe trigger wheel, lets say 36 teeth without missing tooth and cam sync?

so it should be possible to detect rpm and fire from cam-sync...

regards

[fphil]

It may, since from the bench I did not see any error coming up from a fast speed variation done with the VT trigger tool emulator.
btw Have you asked Vems support?.