Slight stumble on accel to cruise transition

[KillerB]

OK im not sure where to start looking so im asking here first.

Engine is a CA18DET with 440cc, completely rebuild ~2yrs ago. 3" exhaust from turbo.

The engine runs great, good power on accelerating, stable idling and cruising. However a problem arises when i do normal to light acceleration and then gradually going to cruise. This means going from like 20% throttle back to 10% or so... Just as I am throttling back the engine is stumbling, like a short hesitation. Its not that big of a problem, but it can get anoying when driving in city traffic.

What could this be?? Fuel or timing related? Are there perhaps some additional correction tables accessed by the ECU when throttling back? I have no wideband logs available atm. All i can say is that afrs are normal during acceleration and cruising.

Heck, im even suspecting the stupid butterfly valves of the japspec head. Came with the engine rebuild...
Any thoughts?

[bachig24u]

See if it relates to the deceleration fuel cut tables. lower the rpm to be 100 above when injection resumes to see if problem is resolved.

[KillerB]

Ill try to do some logs when the weather improves here.

I dont see any deceleration fuel cut tables for the CA18DET however?

[Matt]

Should be called fuel cut and recover