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MAP Delta question


Peace
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Hello
I have a strange behaviour of MAP delta it is jumping and is very hight even at idle with 0% tps. And most of the time it is oscilating.

My car is ITB RB30 so maybe it is normal for ITB setups with very tiny manifold to act like this but i wanted to check with you guys.
Here is a screenshot of my log. Can post a log file but its quite large from a big portion of driving, and i dont know the way to split in into some files.
Screen shot 1784236675_2022-07-2811_40_37.thumb.png.aae3506431d91e46c88155a72b2b8bc8.png

Screenshot 2
1415451234_2022-07-2811_45_04.thumb.png.d8044ce5c23b3f4be98decdd72e5df9c.png

Wanted to give CLL a try but found i need to set up realy high map delta threshould so CLL begin to function, if i put reasonable values like 10 or 20 KPA/100msec CLL stays always in LOckou:Map Delta
Anyone have expirience with such behavior should i just bump up Map Delta lockup or i need to search for trouble in my wiring, sensor?
But map reading themself is pretty stable not oscilating

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I just looked at a log from the last GTR I tuned and it has about +/-20 MAP delta at idle - pretty sure that was quite stock though.  

You do have an adjustable MAP filter in G4X but I think I would leave that on low and just bump the MAP lock out up.  

BTW, those sections in your log where all the lines go flat is due to coms dropping out or not keeping up.  

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Thanks for replying i also thought it is because of very small plenum on a GTR
What can you suggest to diagnose comms?
I was not looked into details because it was a log of a 50km run without throttling hard or anything was just driving along the highway. And i was not worried about weirdness of log.
 

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14 hours ago, Peace said:

What can you suggest to diagnose comms?

Does it have resistor spark plugs?  In the communication settings, try swapping the port between the USB and COM (instead of auto) options, often one will be better than the other.

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