I get ehxuast bangs when I keep the car at high rpm and then release the gas pedal. My O2 readings is pretty good, so i guess to much spark or to little. How to tell?
And how do you program your overrun spark? To you have little timing at a low Kpa @ hig rpm?

thanks

 

DFCO.
Decleration Fuel Cut Off, cuts off the fuel on decleration.

It just might have a bang depending on what your doing. Even with port injection there is some fuel in the runners, plenum, and it may take an instant to vaporize, even with DFCO. And a exhaust leak can cause the bang also.

 

hmm ok ..

Where do I adjust the DFCO in my 730 ?

 

There's a series of settings for it. Might look around for commented Hac.

 

so what do you basicly whant? To kill the fuel when you let go of the gas? Wount that create a lean condition? Cant you controll that with the VE tabels. Just take away fuel in the low KPA areas at high rpms?

 

You could also try to pull some spark in the low kPa overrun areas, see if it helps any.

 

No fuel is not lean.
Lean still supports combustion, no fuel means no combustion.

 

true..

So what that do is to cut fuel when you let go of the gas from wot? WOunt that kill the engine?

 

DFCO cuts fuel only for certain instances, rpms, deceleration rates, etc. If you happen to push the clutch in, and the rpms hit a certain point, the ECM will feed fuel back in to keep the engine alive...and if you never push the clutch in, then there's no problem since momentum and the car's mass will keep it spinning.

 

where can I find a HAC to tuenr cat for that?