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I meant that the flywheel was taken apart and bolted together in the wrong place. If your timing is off this is all that it can be really. It normally is right around 40 degrees off.
20 degrees after top dead instead of 20 before. It is easy to diagnose. You can pull the crank sensor out and spin the motor over so that the weight with the magnet on it goes by. That should be the reference for the top dead 1 fire if I remember correctly. If you take the transmission out you can see the alignment marks for the flywheel and the ring gear. There are dots to align it properly. \
If you put an aftermarket ignition on this will still be off and most will not allow you to adjust the timing that much.
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That (flywheel off) was exactly what i had in my mind. But i was not able to check if the flywheel is in right position. i mean i have no clue what is the proper phase of crankshaft sensor signal according to let's say position of first piston at a certain moment. i was desperately trying to get this information at MB dealer but they claim that they do not have such data.
if I understand you correctly then the magnet no. 27 from the below picture is exactly aligned with crankshaft sensor when piston 1 is at top dead center? Can you confirm this?
I am surprised that it is possible to bolt the flywheel and ring gear incorrectly.
You say that i will have troubles also with aftermarket ignition system due to possible wrong position of a flywheel ... but you assume i will use the existing crankshaft sensor. No, i will not use it. I will use new sensor mounted somewhere at the front of the engine. Further discussion is appreciated. Thank you !!!
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my w140 reads -2, -5 deg at idle :/
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is this a typo or I do not understand? So you measured from -2 to +5 degrees at idle? And the reference was cylinder no 1? I mean this is very retarded ignition. -2 degrees is after the TDC, is that right? Can you comment this a little bit more please.
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samosali:
The combined flexplate/trigger wheel of the M119 engine is a one-piece welded and riveted assembly. It is located on the crankshaft flange with a dowel, ensuring that it can be attached in only one position. The trigger wheel is of 63 teeth minus two (and does not have a flying magnet). The "minus two" window defines the crankshaft location for ignition timing, and the total tooth count is used to signal engine speed. The sync sensor(s) identify specific cylinders for both ignition and injection events.
You have mentioned a variation in ignition timing of 30 degrees. Is that a cylinder-to-cylinder variation? Or a random variation of up to 30 deg. at idle as observed at #1 cylinder? Has the same timing light been tested on other engines? Is it steady in other situations, or does it exhibit scatter when used on other engines?
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Thanks for your detailed description. It seems that it is not in accordance with the above post. Please let's clear this because it is very important to me. Are there two variants of the flywheel and ring gear maybe? because the picture which I attached shows one magnet. So I would really like to discuss more with you to clear things in my head. You claim that it is not possible to mount the flywheel incorrectly ... which I would like to believe very much and I hope it is so. namely, if this is true than I can conclude that my flywheel is installed correctly. How can i prove this assumption?
as for a variation in timing: for a certain cylinder i measured (with oscilloscope) a variation of 30 degrees (and even more) for very short period of time. So let's say during one second a spark occured from let's say 10 to 40 degrees before TDC for a certain cylinder. More precisely, in one cycle timing was 20 degrees and in next one it was 30 or 40 before TDC. Then 10 degrees, etc. This is very inconsistent and it is true for all cylinders. So I used oscilloscope not the timing light. I can present the results here if you would like to see them. They speak for themselves and they prove something is wrong with timing. Not with injector pulses, not with spark plug voltage chart, but with the timing, so with the moment when the spark plug occurs.
I have two channel scope so I did not measure all 8 cylinders in the same time but as stated above the variation (30 and more degrees) was confirmed for all cylinders. One would expect 10 deegrees maximum because at idle timing should be from 6 to 15 degrees according to my data (alldata.diy).