AIS all over the place

[1991shelby]

Hey NAJ could you please post the vacuum diagram. I do have the original under the hood but it would be so much easier to follow if I did not have to look up at the bottom of the hood constantly.
The guy before me made a vacuum nightmare for me. I already found a check valve (broken) in the line to the wastegate solenoid. Who knows what eles he did so I need to start all over.
I appercaite it. Thanks

[NAJ]

[1991shelby]

Vacuum lines are changed (i am pulling 22-23 at idle). O2 sensor is working properly. AIS still opening and closing at will but seems to be limited to about 5-700 rpm. It does not get stuck higher than 1700 rpm but still flutters.
I was told that the speed and distance sensor will drop idle down when the car comes to a stop. I have experienced this in my car (aprox. 500 or so rpms).
So does the SD sensor tell the computer to do this by closing the AIS?
Are there any other signs the SD sensor is going bad? (my speedo sticks sometimes but just thought it was age)
I am trying to find the most likely route to test first.

Thanks

[NAJ]

You need to connect a scan tool so you can look at all engine control values and see what the controller is seeing, you will also be able to see AIS steps.
The controller is seeing something that is causing it to move the AIS in and out.

[1991shelby]

Since the scan tool needs to be scrolled through to look at different sensors just trying to see what to check first and then go from there. Besides just learning more about how my car works. I can rebuild a chevy v8 and a Holley carb but when it comes to the highly computer controlled cars I need more work.

[1991shelby]

Found two things. The person who had the car before me put all of the check valves in the wrong way (vac. on the boost side). WOW.
Two the autoparts store gave me either the wrong or a defective PCV valve. It was causing vac. problems.
Fixed the check valves and naturally ventalating the crank case. Plugged the AIS back in. I have drove it for around 30 miles with no problems. Idle is normal and hopefully it will stay that way. Time will tell.