Thread: Is it just me or..?

Does the O2 mixture get richer just after lifting off the throttle, especially when completely off?
Which settings / tables are responsible this?

DTPS Load factor i think or maybe DTPS Rpm factor

What to do with these, increase / decrease?

increase the values to reduce the fueling by a greater amount is how i understand it.

TBH, ive made some pretty massive changes to pretty much every table in the decel that might make a difference and the car still pops flames when i back off.

When you let off the throttle, the manifold pressure drops quickly and any liquid fuel in the intake manifold instantly evaporates and is sucked into the combustion chamber. This is what causes the momentary rich condition. Make sure the TPS is adjusted properly and that the Throttle Closed indicator on the Data Screen is turning on when the throttle is closed.

When the throttle is completely closed, the OVERRUN FUEL CUT tables are in effect.
While the throttle is closing, the DECEL PARAMETERS determine when decel fuel reduction is to occur and the dTPS DECEL and dTPS TPS FACTORS tables determine how much fuel to remove.

Dave

Edit: I should add that these parameters/tables are on the ACCEL/DECEL tab.

Not to complicate things or get in the way. But backfires are generally always caused by a lean cylinder condition, so consider this when you are adjusting said tables.

Walker

As Dave said, this is a natural result of the tau puddle evaporating and is often augmented by extra fuel dictated by the ECU. If you don't have this rich condition the engine brakes quite suddenly which feels unrefined and can promote bucking.

@Dudeman258, did you mean afterfire (explosions in the exhaust) or did you really mean backfire (explosions in the intake)?

Mine is definately explosions in the exhaust, my rear bumper can attest to this, and driving in the dark last night its lighting the road nicely. It might just be a symptom of running "slower" 850cc sard injectors.