Hondata

so i have DC2 B20VTEC with CP 12.5:1 pistons etc, Portflow worked head, Skunk2 pro2+ cams etc, endyn hand ported in. manifold, 65mm TB, bisimoto 'ramhorn' ex. mani, 2.5in exhaust...

fuel is set to 80 psi with aeromotive 13109 FPR, ID725cc injectors, S300 in new ECU. car is dyno tuned and made ~157kW, which was good.

i am fairly new to all this, but think the LTFT is an obvious thing that road tuning can address:

car bogs on cold starts, needs to be nursed for ~120 seconds to maintain RPM... any load can kill it.

but as seen in the attached datalog, this is my warm engine in cool traffic and the long term fuel trim (LTFT) changes whilst idling from 0% to 8% in 60 seconds...

QUESTION: should i just leave it, and let the LTFT sort it out, or should i change the low cam fuel map to improve starting, whilst leaving the high cam map as dyno tuned?

plus: what would happen if i changed the 'short term fuel trim settings'

log

When properly tuned LTFT should be as close to 0 as possible. Both issues sound like it just needs additional tuning. The fuel tables and compenstaions are more than likely what need to be adjusted.

Spunkster wrote:When properly tuned LTFT should be as close to 0 as possible. Both issues sound like it just needs additional tuning. The fuel tables and compenstaions are more than likely what need to be adjusted.

thanks! so i have to reduce the low RPM fuel tables? since i don't want to affect the WOT tune...

can you look at the map and give me a guide as to how much to take out?? is my start up enrichment OK?

at idle the duty cycle is <1% - will reducing pulse width much more affect the idle?