Sorry for the long post!

Does the 89 ka24E also have a butterfly valve in the intake? If it does what RPM does it open and how do you check to make sure it works.

The problem is that I just dynoed my car and it's great up to about 4.5K rpm. then it drops fast. The guy told me the hp is low for a 240.(He just sold his) It also starts to run rich. I figure if the valves don't open then it won't get enough air and begin to run rich, hence my lack of power.

Up till then the torque is great, between 120lbs and 132lbs from 3K till 4.5K.
The chart doesn't show before 3K, but it looks like the torque would have continued at that level to 2.5K rpm atleast. By the way I have a 2.25" catback, a MSD, an Injen intake, and electric fans, air temp mod. I don't need a tune up.
Any Help/suggestions are appreciated!

 

there is 2 butterfly valves in the ka intake. the main throttle body valve opens and closes with the throttle position. the second one is buried somewhere deep in the intake manifold. suppose to but for better low end torque or something.

 

APEXi has a butterfly valve...