M30 running on 3 Cylinders !!! help

[Javier]

If DME relay remains energized no mater key off, then DME should be damaged, probably, output transistor to DME relay (DME pin 36). (or DME relay contacts seized, of course, doubt it though).

In this page posted by Shogun some time ago, http://www.e34.de/frames.php, after the link "Schrauberecke", after the link "Tips und Tricks", after the link "Schaltplan der Motronic" is a drawing of DME 1.3, it shows the internals of DME. Don't know if you should mess with it, but some one knowledgeable in electronics with the drawing may help you debug it.

I think, and do not quote me on this, that what you refer about the Idle control does not mean it is not working. Idle control is there to automatically adjust idle wile throttle is closed. Guess it closes when you throttle up.

Originally, you referred that 3 cylinder issue starts when alternator kicks in, is now permanently (as your alternator is always in). If it is, revealing a change on the issue on the new alternator condition, have you tried to disconnect the alternator and check for 3 cylinder operation? Just curiosity to establish a link, if it is there.

Javier

[grave77]

ok ... seems it was solved now. I was fed up and I took it to a workshop close by, while driving there the car was fine no missfiring no 3cyl thingy ...
next day they called me and told me that the injectors was really bad. and they were behind the problem. DME was ok I still didn't know what they did to fix the ACC switch. my only interpritaton was that the injectors were drawing higher current when the alternator was on that causes the DME to stop the signal, can this be it?

I will get the car today and I hope that this was my problem ... so it would be added to the forums archive.

I'll keep you posted when I get it back.

[pink-planet]

Congratulation on solving your car problem, hope that it will run now smoothly without any problems

[grave77]

well I took it on a ride today ... ran smooth ... still on OEM Chip ... I will restore the EAT soon. but they installed me single hole injectors instead of my old 3 hole type. they said they are newer or like the E38, E39 injectors. I also replaced the AFM and vacuum hoses too. tomorrow I will have a long trip for a better test.

[Rustam]

ok ... seems it was solved now. I was fed up and I took it to a workshop close by, while driving there the car was fine no missfiring no 3cyl thingy ...
next day they called me and told me that the injectors was really bad. and they were behind the problem. DME was ok I still didn't know what they did to fix the ACC switch. my only interpritaton was that the injectors were drawing higher current when the alternator was on that causes the DME to stop the signal, can this be it?

I will get the car today and I hope that this was my problem ... so it would be added to the forums archive.

I'll keep you posted when I get it back.

I would ask them to tell me what exactly the problem was, before paying the money...

[grave77]

well as I said, they replaced the injectors, I got the old ones. the electrican said that there was a short circuit in the fuse box, that caused the ECU relay to stay on. this one I caused it by mistake since one of the fuses burnt and I used a thin wire to replace it and that wire was connected to the one next to it.

tomorrow I will test the injectors on an external power supply with an accurate Ameter.

I took a garuntee incase things went wrong.

The main problem is that MarkD wasn't able to trace the Chip code and tell weither there was a routine that makes the ECU run like that on a certain error or not. but today was the longest trip I made since it started. and I had no problem. tomorrow is the biggest prof. I have a 100M trip, am sure it would tell.

Thanks for you all assisting me in this especially you and Javier, I think I leared hell out of it.