s13 sluggish (boggy) with light throttle, but goes fine at higher revs????

[blues14]

I just had a shop drop a fresh ka24e into my 89 auto, but the car is boggy and sluggish at low revs, but once above 3400 rpm it runs fine. could it be the timing? its a california car with a federal Emissions motor, which has also caused a check engine light since there is a sensor missing on the intake manifold, could that more likely be the cause? how do you adjust the timing?

[Checkered-Member]

Do KA24E’s come with a secondary butterfly system?

[silencer.1]

Do KA24E’s come with a secondary butterfly system?

Yup, they do.

[Checkered-Member]

Yup, they do.

That can be the cause, not likely, but you never know.

The secondary butterfly system might be opening late, making the engine sluggish at low rpms,

i'm of no help