Missfire starts at 1700rpm and getting worse at 2200rpm

[Morty]

Hi,

this is my first post except for adding my project earlier today.

I am currently setting up an AEB (VW/Audi 1.8T-20V) engine to be controlled by a VEMS 3.3.
The engine so far is standard when it comes to injectors (240cc) and turbo (KKK K03) and with OEM setup it delivers 150bhp.
The ignition is setup with original COP's, ignition module and controlled by stepper outputs.

My installation is in a home built car (see projects).

I have what I believe a trigger fault that starts at 1700rpm and getting worse up to 2200rpm where it will not rev higher at bakfires when releases the throttle. I have tried many different setting in MT, trigger tooth, changed polarity on the VR sensor signal etc. without any luck.
I have even tried to shim the VR sensor 0,5mm to see if made a difference, but no difference.

The VR sensor is OEM and uses a built in 60-2 on the crank shaft.

I am running Firmware 1.0.73 and below is my latest MSQ and log (see latest part).

http://www.vems.hu/files/Morty/Morty200905020859.msq

http://www.vems.hu/files/Morty/Morty_log200905011150.xls

Any suggestions are welcome as I am not finding my way out of this.

Best regards
Magnus

[rob@vems.co.uk]

You have more pressing issues with all those RPM spikes and trigger errors - unless they're when you've powered the ECU up and down.

When its running though you're quite right about the misfire - you've not got an incorrect setting in the ALS, Launch control or rev limiter have you?

[mk1classic]

I had similar problems with missfire at approx 1700rpm on my 1.8T 20V setup, unfortunalty the engine died the day before Jorgen was coming to town. (time to remove the old engine... now)

[Morty]

ALS, EGO, Launch control, crank min period are all disabled.

I have uploaded a file on YouTube today showing Megatune and tachometer when this occurs.

http://www.youtube.com/watch?v=vyT7ZIbXytM

[Morty]

Today I have tried to reload the Firmware 1.0.73 Final and still the same issue as before.

I will see if I manage to borrow an oscilloscope tomorrow and log my trigger signal.

[Morty]

Today I borrowed a Fluke Oscilloscope from a colleague.

I have also been in contact with Jorgen a number of times during the evening to analyse the issue.
Here is a screen copy from the oscilloscope at 1800rpm where it starts to missfire.

[Morty]

I am still struggling with this. Jorgen has sent me a filter that rectifies the triggersignals to be 1,04V for the first tooth and 0,80V for the rest of the teeth. According to him the triggersignal should be good now.

Yesterday I checked the signal from the stepper output to the ignition module with the oscilloscope and it was obvious that the ECU cuts the spark and no signal is sent to the ignition module.
I can not see any trigger errors in the logg. ALS, Launch, Crank min period, Rev limiter, fuel cut are all turned off. What are the preconditions for the box to send the spark signal?

[GintsK]

On video seems not like a triggering problem.
BUT if i look to my two years old cal files, i see that angular width of tooth is 120 and missing tooth is 240.
It is from 1.0.73final.

On new firmwares thanks God this values are much more user friendly. Degries are degries 1:1.

 Also. What coils you use? 1.8T use passive COPs. You have only two outputs configured. Are one output directly drives two coils??

Gints

[Morty]

Ok , I will try to change the angular width of tooth to 120 and missing tooth to 240. How did you find out the values for these settings when you where using the 1.0.73 final firmware?

Yes I am using the passive coils with 3 cables and the ignition module. How do you mean when saying that I only have two outputs configured?

[GintsK]

I've found these values in my old msqs from running cars. But where you found yours?

Your ign outputs are OK. I opened your msq with wrong Megatune previous.

[Morty]

The values are picked from a page at VEMS.hu. I tried your values yesterday and it did not make a difference. Since they are so far from each other and no signs of different behaviour, I believe this setting is not used by the system...

What is the typical voltage from a VR sensor? Mine is 13,2V at first tooth and 7,6V on the other without Jorgens filter and 1,04V and 0,8V with.

[Morty]

Looking at my h[1] and h[2] directly from typing mct in terminal gets me confused.

I got these values:
h[1]=00 00 00 00 00 00 00 00
h[2]=38 48 68 58 00 00 00 00

As far as I read today the h[1] line is the trigger
and the h[2] is the ignition

How can it be that the trigger line is 00 al the way and the engine still runs (on idle at least...)?

What should it be with a 60-2 trigger wheel?

The ignition is setup to run the stepper outputs but is this right? I know that the order is set to 3,4,2,1.

[rob@vems.co.uk]

Firmware 1.0.73 didn't use h[1]

[Morty]

Thanks!

Is h[2] correct?

[Morty]

Now the sparks cuts and missfires are gone

The reason for this was the cam sync and too high amplitude on the first tooth.

Jorgens filter together with waste fire works fine....

Now hopefully the fun bit starts!