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Nettlez

RPM errors

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So I have an issue with the RPM on the log jumping around at higher revs. The engine is a bmw m50 turbo and the original crank trigger wheels gap used to line up almost bang inline with the cam trigger so I have changed the crank trigger wheel for another to move the two apart, I hoped this would solve my issue but it hasn't.

The two triggers are both vr type sensors. I have tried to setup my arming thresholds to suit a third of the voltage but anything past 2000rpm I need a value greater than 7 but the link g4+ ecu wont let me put a value in greater than 7. 

I have noticed there is also another setting called trigger filtering but the help file doesn't give any clear information on when to use this, is this a setting I should try adjusting to help with my rpm jumping around? Is there anything else i can look at that could be causing this?

The ignition timing I have seems to be a lot lower than others I can find in the internet which was another point towards trigger issues in the hp academy course

I have attached a log, my map and a scope at idle

any help appreciated

 

log:

http://s000.tinyupload.com/index.php?file_id=37506189993904150499

Map:

http://s000.tinyupload.com/index.php?file_id=46465854529146560910

Scope @idle:

http://s000.tinyupload.com/index.php?file_id=00069227142569558386

 

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Your trigger 2 pulse does not look correct for a Reluctor sensor as it is only showing positive spike.

Can you try it set to Hall/opto with the pullup on and grab another trigger scope 

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That is a much preferred signal. I would be focusing on the tooth after the gap and checking it is crossing zero at the higher RPM 

 

 

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Im going to paste my reply from your similar post on the HP academy forum for anyone interested.

I dont see any signs of trigger issues in the log you attached. There is really only one short burst to 6000RPM in the posted log so that may not tell the whole story, but dwell is well controlled and the Engine speed ROC parameter is pretty stable - both of which suggest the ECU is getting good consistent trigger info.

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Thanks Simon, I will take some more logs at higher rpm 

I was comparing my engine rpm and engine speed roc to the one in the trigger error webinar and in the log he shows his roc barely goes above 250 yet mine is going way over 500 and my rpm curve is no way near as smooth? Which he mentions means I have trigger issues??

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