K20 frank 1250 to 2500 rpm throttle 0 to 100 engine is very jerky

FlashPro questions & answers specific to the FN2 European Civic Type R
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typer86
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Joined: Sun Oct 28, 2012 3:17 pm

K20 frank 1250 to 2500 rpm throttle 0 to 100 engine is very jerky

Post by typer86 » Wed Sep 20, 2017 8:45 am

Hi Hondata

I am currently tune a K20 frank with K24 block with 12.5:1 high compression piston.
The custom engine is working fine on the FN2 but in the rpm range: 1250 to 2500 if the throttle plate is full pressed from 0 to 100% (WOT) the engine is jerky until 2750 rpm is reached. If the pedal is released the engine will shake again...

- We have tested different ignition profiles to fix the issue (first it was to much ignition advance...)
- Throttle tip in retard values
Maybe it is a issue with the VTC cam or switch between open/closed loop? I have also noticed, the ignition is jumping around between positive and negative values if the throttle is released...

To avoid the steal of the calibration - I have sent the calibration and logs via email to you.

Did you have any idea what is the cause of the engine jerks?
Thanks for checking the log.

BR

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Hondata
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Re: K20 frank 1250 to 2500 rpm throttle 0 to 100 engine is very jerky

Post by Hondata » Wed Sep 20, 2017 1:41 pm

Have you adjusted the injector dead times for the 410cc injectors?

I would change the VTC setting so that the cam does not roll back to 0 upon decel.

Also try disabling the secondary o2 sensor.

Otherwise you will find that it improves as the fuel tables get dialed in.
Hondata

typer86
Posts: 312
Joined: Sun Oct 28, 2012 3:17 pm

Re: K20 frank 1250 to 2500 rpm throttle 0 to 100 engine is very jerky

Post by typer86 » Fri Sep 22, 2017 2:58 pm

We have fixed it. Thanks for the tipps and directions to looking for.
it was the combination of VTC and ign profile which must be adjusted to working fine.
Fuelling will be adjusted now and the calibration is finished.

engine is running fine now :-) Successfully tuned.

BR

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