After getting the 7 back out on the road after winter, I noticed that vacuum readings are around 15 psi, as opposed to the usual 18. Trying to think this through, I find that air temperatures are still a little low with temps in the 30s. However, I noticed that my idle speed is running around 900 RPM instead of the usual 750. This would seemingly cause the loss of three pounds of vacuum but what would cause the idle to slip in the first place? Car seems to run perfectly, otherwise, 10-8-10 boost and all.

 

Adjustment on the throttle cable could be off or you might need to make an adjustment on the throttle body. The throttle cable is a no brainer and the throttle body has one adjustment on the front and the split air bypass on the bottom.

 

Thanks, you've saved me an hour or more of hunting. I'll find the details in the service manual. I'm still a newb at most of this.