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Fuel Overrun cut off delay, ITB issue?

Posted: Sun Mar 12, 2017 4:54 pm
by K20a2tuned
Hello guys,

We believe this to be the problem but just want confirmation as we can't test before race day.

Car is a stroked 2.2 running ITB's with carbon plenum and Kpro V4.

We were testing 2 days ago and every time at two hairpins on the circuit the car wouldn't go and ignition had to be cycled to get any movement, car would the. Be jerky and misfire.

After studying the data we saw that this only happens below 4000 RPM and requesting medium to full throttle.

We were unsure of the issue that day and tried many things. Upon looking over the map etc on the evening we came across fuel overrun cut off delay.

The map settings were all set to 0 for any given RPM and the ECT settings were set at 4000 RPM.

Does this sound plausible as the issue? Data logs on our own Race Technology system show full throttle request but RPM decreasing, car doesn't pop / bang likes its ignition, it's much more like it's not allowing fuel to recommence.

The map can be viewed and downloaded here:
https://www.dropbox.com/s/z7cl8ezlalydx ... p.kal?dl=0

Overrun settings from the day when the problem was occurring.
image.jpeg
Data showing TPS and RPM. Blue the problem does occur, as can be seen full throttle requested but rpm decreasing. Red full throttle requested and RPM Increasing problem doesn't occur.
image.jpeg

Re: Fuel Overrun cut off delay, ITB issue?

Posted: Mon Mar 13, 2017 9:29 am
by Spunkster
Without the calibration and datalog showing the issue it is hard to say what it might be.

Re: Fuel Overrun cut off delay, ITB issue?

Posted: Mon Mar 13, 2017 11:36 am
by K20a2tuned
The calibration is linked above the two images if you're able to view?

Thank you.

Re: Fuel Overrun cut off delay, ITB issue?

Posted: Mon Mar 13, 2017 11:58 am
by K20a2tuned
This is the setup. Map sensor is placed In the backing plate taking the reading from the Carbon Airbox.

Car runs great, idles perfectly.

laps perfectly except for when we drop below 4000 RPM.
image.jpeg