Problems!! It started a morning 3 days ago, the enginge started duing strange tings (worse then reaching the rpm-limit) resulting in "bang" fra exhaust and a "jumping car", when reaching 5000RPM. After it been through the carwash it started fine but 10 minutes later it would not start. When it finaly started it was hard to keep running and MegaTune showed everyting from 0 - 8000 RPM, the fuel-pump relay was going crazy and so was my shift-lights..? After some time it got better and better, but It has been coming back :(

I thought it was because of moisture the hall-sensor vas going crazy, but should I not bee able to see the "spikes" in a datalog?? In this datalog I was trying to keep the car runnig!!

Yes it might bee water in the secondary ignition somewhere, because it started againe after I been driving in the rain and after the car has been indside fore a day there is no problems. But how can it bee that I can see the RPM in MegaTune going crazy, but not in a datalog? Can the datalog not detect "fast" spikes?


The engine has been running fine a few days now :))) The problen was a "air-leak" around injector #3 :o

I added the original Bosch ignition-module so I have not been looking more on the dwell settings (they are both just 2mS).


As PeterJ? also write my car has got a bad habit by starting "misfirering" (at least I think it is, because lambda does not go lean) after it has been runnig fine fore 15-25 min. or so. It is not when it get warm it starts but 5-10 minutes after it has reached the 90-95' clt (where it also stays), and it just get worse and worse until it get a break. But short break = misfirering again after short time, so it got to bee something to do with temperature, right?. Any ideas??

Too hot coil might cause similar behaviour.

When i look at the data-logs Dwell is always 2, even though I set it to 3mS??

What does LCD show ? Maybe it's a vems.ini problem ? What is your VBatt ?


?? I was going to change en value in the Lambda-map when I noticed that when I chanced the value down (towards lambda 0,9 (richer)) MagaTune? road wrote "leaner". This is just the "note" being wrong,right?

Check the table printed out by "Man" "mct" to be sure. 0x38 is stoich, above 0x38 it's richer. below 0x38 it's lean. lambda = 256/(200+ lambdacorr) Yes I did it right then.. Thanks


It is running :) I installed all the wires and stuf this weekend and after recharging the batteri it started yesterday evening. I have not had the time to tune it properly yet, but I have a few thins in the config im not so sure about so please put a comment to this (I use the original hall sensor and distributor):

primary_trigger=03 # this combination is not really used, We use filtering with coil-type trigger (07). Actually, traditionally we use FF for rising edge (same as 07, the higher bits don't care) and FE for falling edge


crank_minper=FF # "Cranktrigger min. period [16 usec]" is way too high (where did you see this?), use 60 or so. Period times (period=180 crankdeg for a 4 cyl) shorter than this are considered bogus (trigger error) so this value should be below the period times seen at max RPM

The values below don't matter for coil-type trigger without camsync.


trigger_tooth=0A # ?

another_trigger_tooth=12 # ?

tooth_wheel_twidth1=B4 # ?

tooth_wheel_twidth2=FF # ?



reset_engphase_after=D8 # ?


Q.2)When i open my Lambda Table in MegaTune (r18 and Firmware 1.0.12) the numbers are all wrong..


I can get the same numbers out of the board again with the Terminal-program as I put in.. But they don't show in MegaTune?

The lambda-tuning works good with recommended latest released firmware (GenBoard/UnderDevelopment/FirmwareChanges currently v14_rc1) and latest MegaTune (verify with mct that MegaTune vemsv3.ini is acting properly). Yes It works again with the new firmware and MegaTune r23.

Q.3) If I download the new Firmware 1.0.14 to the board, I want to to do some new testing on the table but now I mounted all the transistors in the box.. Should I just put a lightbulb on all the outputs or what to do?

yes. Actually final testing is done after mounting the TO-220 FETs and IGBTs and clamping them to the Alubos (the IGBT-s can short to neighbor or case if not done right). Likely you have a few econoseal recepticles that you can hook up.


Q.1) I have a 2-pin idle-valve, but what settings should be used fore this.. PWM, ON/OFF?

Any solenoid works with ON/OFF. Only some work (well) with PWM.

  • what is resistance ?
  • anything known about original application? Does it have real idle-air control or just simple "fast-idle" ?

Does some one use the the same valve, and have a config-file that I can see or just some input to what settings to use?


Q.2) Is there some way to test the idle-output?

  • which output did you choose in iac_sol_channel ?
  • PWM type iac output can be tested with forced iac.position: mdi01..mdiff . Do NOT forget to set back to mdi00 (or reboot) after you executed the tests to revert to normal control.
  • alternatively it can be tested like any other digital output, with mdh.. command. See GenBoard/Manual/DigitalOut/Table. In this case, do NOT forget to set iac_sol_channel=FF to prevent interference and set it back after the test.


I got the new Megatune "mt-r014" and I tryed to use the firmware that was together whit it, but then I got no "output" on inj. or ign. and the the config and table was the same..?

No problem.. Just needed to chance secondary_trigger to "02" instead of "FF".


I have 4 ignition coils from a BMW 318i E36 that I'm planing to use, but I'm not sure how to connect them.

They have 3 pins: 1, 4a and 15 and I measure 0,7Ohm between pin 1 and 15.

Q. Are they like the coils from a A4, showed on IgnitionPage/COP?

Q. If they are like the ones from a A4 and pin 15 has to be connected to Vbatt, should "IGN_OUT" then be inverted (MY_CONF += -D IGN_OUT_INVERTED)?



Q: I use the latest version of MegaTunix from this side is that the right? I use Windows..

A: Much is changed in the latest CVS version, wait until the next release or compile megatunix from CVS.. - OK

Q: I copyed the files from firmware/doc/megatunix to ~/.MegaTunix what else to do?

A: Remove the CVS-directorys from the .MegaTunix-directory - OK

Q: What should I do/write to get CVS to download a older version like Nov24 instead of the newest?

A: Example copied from GenBoard/UnderDevelopment/FirmwareChanges:

set <enter>

set HOME=c: <enter>

cvs login<enter> ( <enter> again for password, ignore any error messages )
cvs co -D "2004/11/24 16:00" firmware <enter>

Re: ..Yes I have seen the example but I don't get it..

I have taken a screen-dump, could some one write what i should write to get the firmware from nov. 24?

A: Dont use GETFIRM.BAT for this. I've made some changes to the answer above that should get you there. A directory named "firmware" will be created.

Re: Thanks that explains.. Now it seems to work, but when I use that firmware (2004/11/24) it only write "egt:03xx" in the display.

Q: Dose anyone know why it only says "egt:03xx" and not RPM and so on?

A: Because you are on the wrong lcd page, have you uploaded config ? You can change lcd page with the arrow keys on keyboard or with the mlpxx command (where xx = 00 - 07) - Ahh.. Thanks a lot.

Q: How can I see if I really got the right firmware, is there a release-data in it somewhere?

A: unfortunatly not, you can use the release on this page to be safe: GenBoard/UnderDevelopment/FirmwareChanges - OK



I tried to use Mega-Tunix but it said something about not finding or detecting firmware. Does something have to be setup in my_make or somewhere else in the firmware?

Did you follow the steps on MegaTunix page ? (copy files from firmware/doc/megatunix to ~/.MegaTunix (files are in cvs head, not the nov24 version)).

After I copyed those files in to ~/.MegaTunix, MegaTunix "findes a error" and shots down when it trys to connect to the board (don't if the board is not connected).

Then I tryed to upload the newest firmware where I copyed the "megatunix-files" from, because I had version from before nov24, but the board dose not start up whit the new firmware.

Q: Should it work whit the old firmware, and is there a problem whit the newest firmware (got it with CVS)?

A: The firmware from CVS HEAD is not production ready. You should revert back to the nov24 version for road use. What is the error MegaTunix finds ? Does it detect firmware properly ? I hope you are using the latest cvs MegaTunix version, that might solve things for you, good luck; report. - DB

Re: Windows makes an "error report", I don't know if there is some thing i that, that can tell you what error it found..?

I am using XP and 2000 on my Labtop.. I just installed MegaTune and it looks nice. Last time i tryed it (some months ago), it did not have all those nice options, or maybe I just did not installe it right then.

I'm working on putting Genboard onto my Golf 8v right now as well, email me or post a message sometime. -Where can I finde your mail-address? on my MembersPage/JimW


Hey I have a few questions I hope some one will take a few minutes at answer:

Q: Where and how to disable this self-learning thing..?

A: to disable VE learing: ve_learn_conf=00

Q: Where and how to adjust/disable closed-loop?

A: to disable ego correction, set ego_minrpm very high (above rev_limit value) ego_minrpm=60 -> 9600 rpm


Q: From which cars can I take ignitioncoils for dummy ignition, don't they have to have a "turns ratio" on about 100:1? Any links to places i Europe that sells suitable coils?

This is one advantage of DummyIgnition: almost any that is used for electronic injection. Turns ratio over > 99 is OK. 120 .. 200 seems to be the standard for electronic ignition. The reason is so that max voltage over the IGBT is lower.

If (sparkplug_threshold_voltage / turns_ratio) > IGBT_clamping_voltage (which is appr. 360..420V) than the IGBT will clamp => no spark (and not good anyway).


I read a little about this OutputTrigger but have a few thing I would lige to get straight:

It works. Thanks Marcell - great!



Plans to test the board on my desk..


Something goes wrong when installing Perl and win32:serialport. A: I had some problems when downloading win32::api with PPM so i downloaded win32:api from:, unzip and install instuctions are included in README. -Johan. Thanks a lot, that works.