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Random trigger/RPM issue Subaru EZ36


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I'm having a random breakup that seems to be mostly load related.  I can rev the engine without load with no problems.  Part throttle will go right to 7000 every time.  If there's boost involved it will more often than not break up.

I posted a log where it happens followed by a clean pull.  The trigger scope is under load around 6500 RPM if I remember right.

This just started happening with my current engine.  It's a Subaru EZ36 destroked to a 3.2.  I had an EZ30 for a year with the Link and didn't have any of these issues.  Same wiring harness.  That engine would pull clean under boost to 7500 every time.  All I did was swap engines and started having this issue.  I did replace the crank sensor, but that had no effect.

Hopefully someone can help me identify why this is happening.  Thanks!


EZ32 44.pclx Trigger Scope - 2024-02-25 10;09;16 pm.llgx ECU Log 2024-02-25 3;55;12 pm.llgx

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Your log doesnt have all the data needed, but I would say most likely it is your MAP limit.

Where my yellow cursor is just before the limiter is activated, your boost target is 109kPa so your MAP limit would be 138kPa, your MAP at the same instant is 136kPa. With the MAP limit advanced mode turned off it has a 10kPa control range so actually starts to cut 10kPa before the limit.  

For future reference, the smallest value in your boost target table should be the minimum "spring pressure" that the system is capable of.  Having a target below that will mean boost control will sometimes jump straight into stage 3 before it has even started to spool.  A boost target of 0 absolute is impossible.  


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Thank you for looking at this and your advice. 

It definitely was the map limit. I must say I see my mistake now and it's one I've made before. My map limit boost targets i set up thinking in psig not psia. 

Car pulls hard now, no more limit. 

Thanks again!

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