Cruise control pulsing (for lack of a better word)

[gottabfast]

I have a Turbo B18C in a 2000 Si, controlled with a S300. When I'm in cruise control around 68-70mph (around 3700 rpm in 5th), my MAP values bounce between 45kPa and 75kPa, AF stays between 13.8-13.6, ignition changes by about 4 degees. If I hold at 70 with my foot on the gas (no cruise control) it stays between 52-56 kPa. Anybody have a fix for this?

Thanks!

[Spunkster]

This sound slike a problem with the turbo setup itself. Without datalogs it is impossible to say for sure, but you are probably just spooling up at that point and that mans that the cruise keeps adding throttle to get it up to speed and this increases boost and causes it to go over speed then it drops downa nd keeps going back and forth.

[crucian]

but you are probably just spooling up at that point and that mans that the cruise keeps adding throttle to get it up to speed and this increases boost and causes it to go over speed then it drops downa nd keeps going back and forth.

This is more than likely the problem.