non start no primary trigger using vems

[QuattroFever]

getting pretty hacked off with this non start issue now.
using vems 1.1.81

Im not getting a primary trigger showing in the trigger log but im getting secondary trigger ok.

The 135 teeth VR is putting out a steady wave on an oscilloscope and the 2nd VR is pulsing....albeit not very (0.6volts when cranking) well but it has ran like this for several months and now wont fire anymore.

I had the ecu sent to hungary for repair and they replaced my mainboard from a v3.3 to v3.6. It started no problem before the repair.

I got it back and it fired up and ran that evening. Shut it down and was messing with a MAT(IAT) sensor. Changed some calibration values...fired it up again, first turn of the key no problem.

was sitting there with the engine running messing with the MAT(IAT) calibration and could hear the fuel pump groaning from low fuel so shut it off and went to bed.

Got up in the morning and went to the garage and got some fuel in a jerry can, got home put it and and it wouldn't start. No spark and no primary trigger showing up in the trigger log.

checked continuity of all the grounds and sensors. ok
checked resistance of the VR sensor both are around 950ohms. ok
engine physical timing ok
all fuses ok
checked VR's with a scope. 135 teeth VR shows a steady wave and 15-20volts

video of the 2nd VR ref pin on the scope -
http://www.youtube.com/watch?v=61np7Um41LY
the lower amplitude waves are from the starter ring gear next to it I think.

just turns and turns and turns....what is going on

[QuattroFever]

2nd VR reference pin - pics

[ATTACH]31168[/ATTACH]

[ATTACH]31169[/ATTACH]

[ATTACH]31170[/ATTACH]

[QuattroFever]

135teeth primary VR - pics

primary135teethVR 001.jpg

primary135teethVR 002.jpg

primary135teethVR 003.jpg

[A80Avant]

although this is a bit beyond me, have you tried reinstalling the firmware?

[UrS4boy]

And they say VEMS is an improvement over the Motronic.

[QuattroFever]

I tried to do it once from 1.59 to 1.7 something and made a mess of it. so when i had it looked at by peter when i had a nonstart issue months back i gto him to upload 1.1.81 at the time.

maybe was following bad notes. I just didnt get the scalars and tables and running .bat files it done my head in.

is it fairly straight forward with the newer FW's

[A80Avant]

grow up!

[diesel des]

I think the voltage on the second vr eg pin sensor is too low. My car would **** about with trigger errors until it would heat up. Then it was ok. I messed about for ages with sensors and welding stuff onto the 7a flywheel. Then I gave in and fitted a 3b flywheel. Been great ever since. Maybe yours ran when its warn, now its cold the voltage is too low. Does the new vems board have the same sensor input setup eg bias voltage.

See if it starts on a pull.

[A80Avant]

yeah, 7A needs a big ***** pin to work properly. ill dig a photo out from mine i think mine was bigger than the dual mass in length

[Jamo]

Have you changed the wires around or have an adapter as per the VEMS AAN install guide?

[QuattroFever]

@jamo ye, reversed polarity.

@diesel des, starts on a pull? Pushstart or towed? Was running all thru that bad cold snap we had. No idea on bias voltage? I am on 7a fly.

[QuattroFever]

ive noticed the v3.3 pinouts are slightly different to 3.6.

There is a pin for ground in the ec18 with v3.6 now. Could that cause problems not having that wired?

My adapter loom was made up for a 3.3 if that makes anything apparent.

[terrybullwon]

Bin it.

[QuattroFever]

gotta tell you, ive considered it in my frustration.

Kind of resigning myself to fitting a trigger wheel to the front pulley and be done with it.

[Jamo]

You should really take this to the vems.co.uk forum so you can get help from mattias / Gints etc