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Random high engine rpm data logging

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Hi,

Im having some trouble with a bmw m50 engine, the car is idling fine then all of a sudden dies, twice now at 59ect. I ran data logging and noticed that on both occasions the data log reported spikes of around 3000rpm, but I was sat in the car and it never went anything like that. What could be the causes of this? Failing crank sensor? It is new but not genuine. Is there a was of data logging the trigger signals? I select them uder setup but then can never see them when watching it back? Data logs attached

 

Thanks

open loop idle died 59 degrees.llg

59 then died again 2.llg

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yeh here it is

BMW E36 G4+ Xtreme Plugin rafe edit - open loop idle - rpm 10,000.pclr

I noticed it because under statistics it said my rpm limit had been reach 8 times, but the cars only been at  no more than 2k(was set at 4500-7000 dependant on ect), I then changed the rpm limit to 10,000 and it went another two counts after running it again but the log doesn't show it going quite that high. When trying to go through it step by step under logging then value list it seems to keep skipping the data where it  shows high rpm? The crank sensor is new but its a euro car parts job. Thinking I might end up going genuine bmw?

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you can also see it in this log when it was running a different map, rpm limit was 4500 upto 50 degrees ect. The only other thing I can link of is that the ecu was a wire in job and the last 20mm where it goes into the female plug is unscreened as the screen goes into the connector but surely there's no easy way round that?

open loop idle died 59 degrees.llg

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Are you using the stock reluctor camshaft sensor?  Set this to Hall effect and rising edge..  The camshaft sync is in the the missing tooth gap on these engines and the Link ECU is not happy with that.  But set as Hall effect / rising edge works.  (pullup off)

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Wouldn't let me upload the pic from my phone. Here's the link to a scope pic at 2500rpm 

<a href="http://s1072.photobucket.com/user/Rafe_Nettles/media/Mobile Uploads/image_zps3yxxcw9s.jpeg.html" target="_blank"><img src="http://i1072.photobucket.com/albums/w378/Rafe_Nettles/Mobile Uploads/image_zps3yxxcw9s.jpeg" border="0" alt=" photo image_zps3yxxcw9s.jpeg"/></a>

 

Are you using the stock reluctor camshaft sensor?  Set this to Hall effect and rising edge..  The camshaft sync is in the the missing tooth gap on these engines and the Link ECU is not happy with that.  But set as Hall effect / rising edge works.  (pullup off)

Yeh im using both stock sensors, this is the non vanos engine which uses both reluctor types, is the sync still in the missing tooth gap with the non vanos? I believe the vanos engines have a different crank trigger wheel? Thanks

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It seems Scott hasnt posted today so I just got on a PC.  Your crank sensor is definitely wired the wrong way.  Swap the wires and re-do your base timing (trigger cal) and you should be good to go.  You shouldnt need to change the trigger 2 settings as per Integral8v's comment, I'm pretty sure it should be fine the way you have it set.  If not we can always try the "trigger priority" setting.

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RPM glitches and Timing scatter are common symptoms of trigger errors.  In your case because of the wrong polarity the ecu is seeing 59 teeth every revolution instead of the 58 that it is expecting.  Every so often it will lose track of position and "skip".

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Hi, I'm here, just having a very busy day :mellow:  Yes, crank sensor polarity looks to be reversed. 

I once had a similar problem on an E36 and found that the factory loom had got hot and brittle over time (under intake manifold) and was shorting intermittently. It is likely a trigger error is occurring. Keep a eye on the Triggers tab of the run time values window (F12 key to open). Does the Trig 1 Err Counter increment?

Scott.

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Did u re-sync timing using a timing light?  If that is ok then possibly the sync tooth is now offset to the other side of the the gap which means you are 360deg out.

so if you have done trigger cal already and it's not firing then add 360 to your trigger offset number

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yeah, -84 or 636 would work.  Now that I'm on a PC again I notice also now your trigger 2 is a bit messed up with a funny double hump - that may be causing an issue too.  Did you reverse the wires at the sensor end or the ecu end of the loom? 

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-87 seems to work well, it's running :-) yet to see if it's logging random rpm data log running. struggling to check it at zero which is the only mark I have atm as it goes to stall. I changed it at the female plug end of the loom, where the sensor plugs in

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So checked the log and no random high rpm figures, result :-) she ran lovely and stayed running, well chuffed. On with the next teething problems now, thanks for everyone's help

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It seems Scott hasnt posted today so I just got on a PC.  Your crank sensor is definitely wired the wrong way.  Swap the wires and re-do your base timing (trigger cal) and you should be good to go.  You shouldnt need to change the trigger 2 settings as per Integral8v's comment, I'm pretty sure it should be fine the way you have it set.  If not we can always try the "trigger priority" setting.

The need to set trigger 2 as Hall effect to avoid trigger errors have been confirmed on 2 seperate m50 non vanons engines (both by Link dealers).  Tried with all sort of settings (trigger arming/filter/trig priority etc) but no good until sett as Hall effect,  But hopefully it works fine on Nettlez`s engine with reluctor (as it should be).

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It seems ok at the moment, it's just been to ticking over, not seen any big revs yet though. What problems do they experience? Trigger one error counter counting? Were they using both reluctor types?

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It seems ok at the moment, it's just been to ticking over, not seen any big revs yet though. What problems do they experience? Trigger one error counter counting? Were they using both reluctor types?

Random rpm apikes and trigger error counting.  And ofcourse misfire when this happens.

  They were using both reluctor types triggers.

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