Acis.

[Island_Yota]

So after some reading im pretty positive that my ACIS system isn't working right. When I first got the car it pulled smooth all the way to 6500, now I can feel an increase in power at around 4000rpm, mainly in 1st and 2nd gear at WOT, I noticed a loss in Low end power a long time ago but didn't think much of it.

My question is where should I start? How can I diagnose if its working or not? What can I do to fix it or is it not worth bothering?

 

[BlackDynamite]

This may help you out bud ;]

http://www.supramania.com/forums/showthread.php?t=40185

 

[Nick M]

An easy informal check is to pull the vacuum line from the valve in the y section of the manifold. The actuator should move when the car is idiling. That removes the vacuum from the actuator, forcing the valve open on the inside. YOu can't see the valve move, but you can see the arm move.

Do it when cool, it is easier on the fingers. If it doesn't move, a likely culprit is a sticky VSV. JJ decribed actually fixing one or two, I simply bought a new one. There is also a possibility of a leaking canister, but that would have a different driving issue.

Removal is by taking off the upper manifold pieces. If you take out the alternator, you might be able to get at it that way. I took my alternator off to remove the VSV for the FPU valve on a GTE, and it is in nearly the same spot.