NefMoto

As it is really hard to find any usefull informations regarding older Motronic systems I would like to ask for assistance in tuning M2.8.1 as used in Opel/Vauxhall Omega (B) MV6 (with X30XE engine).

I have already uploaded XDF file I made and stock binary.

What I am searching for:
 - RPM limiter (by pure "guess" I narrowed my search to 13-14 bytes but I might be wrong)
 - how fuelling works in that ECU (despite using base load TPS/RPM map being corrected by MAF airflow map and other factors like WOT map)
 - which ignition map is used under which conditions
 - is it possible (and how to) to alter closed loop operation

TIA for any help!

RPM Limiter is at D9BC , 16 bit , factor -50  offset 54200.

Could you double check that address as after applying your factor and offset I got -2288350?

LO/HI and you will got result.

Thank you for your answer!
Can you tell me how have you figured this out (taking into consideration "strange" offset and factor)?

Something like this :

1) 8 Bit is B7 03 starting at D9BC
2) Invert to 03 B7
3) Convert to DEC = 951
4) 54200 – (951*50) = 6650

Ok, I got that... I was asking how you found this address, factor and offset? Do you have more informations about this ECU?

Nope try and error , and using informaton from some BMW DMW dams/mappack I got over time. Many of early motronics has rev limiter in front of map start in that area. So its not so hard to find. This ECU Ive tested many times.
N/A tuning of this engine is very good because car is pig rich stock with lower igntion.
Still trying to find injections constan.

I know about the fuelling (I have Zeitronix ZT2 with LCD displayed installed) and ignition.

I am not sure if there is injector constant in those ECUs. To be sure one would have to dissasemble the bin (it should be 80C517/80C517A/80C537 CPU based, it does not use internal memory but uses XRAM) - I tried some time ago but did not suceed as I do not have any experience with microcontrollers nor assembly programming.

EDIT:
I would like to ask if you know at how high airflow those ECUs stores DTC 74 - "MAF voltage too high"? I am constantly hitting that at ~6300-6400RPM but can not find the exact airflow...
BTW. I am getting AFR in the range of 10.8-11.1:1 at >70% throttle (but not WOT!) using stock fuelling from "AF" X30XE ECU on Z32SE with custom camshafts... At idle it reads ~19kg/h airflow killing my urban fuel consumption (it means ~2,1-2,5l/h without A/C at idle to achieve lambda=1) - that is way I would like to know if it is possible to change when it is operating in closed loop (I would like to make idle and very little load open loop and run at lambda=1,1-1,15).

Sorry for replying to myself - today dynoed 230HP@6350RPM, 305Nm@3650RPM with:
 - AFR falling from 12,5:1 @4500RPM to 10,3:1 @7100RPM (just before engine speed limit)
 - stock Vectra B i500 ignition advance

Second run with stock X30XE fuelling and ignition advance gave me 219HP@5750RPM and 303Nm@3700RPM but AFR was below 11,0:1 from 5700RPM.

I can confirm that rev limiter is as RS-MAD wrote! Thank you again.

Now - I have more issues - all 4 maps I had described in my XDF as idle engine speed do not work as I want them to - I can use them to decrease idle speed but I am not able to increase it. As I am running wilder cams my car have issues idling @600RPM or 700RPM (I have 1 ECU with increased idle speed by Tech2 diagnostic tool). I need around 800-900RPM idle speed and I do not know how can I achieve that (I tried setting those 4 maps even to 1200RPM with hot coolant but still got desired idle speed @600/700RPM).

Im quite sure idle is something like duty cycle map not exactly rpm map .. I need to take a look at ... :)

Have you found anything regarding idle speed?

I must admit I do believe it is written as exact engine speed target because you can see desired idle engine speed using Opel Tech2 diagnostic tool...