Idle problems, we've all got 'em. It seems like I also can't get away from vacuum problems. I replace a hose, and next thing you know, there's more vacuum woes. Anyway, my 82 K-Jet likes to "hiss" a lot. It does it when coming off idle and when returning to idle. The throttle response is VERY slow, especially when it's cold. It's now at the point where whenever I'm applying a little extra throttle (like to go up a slight hill on the freeway) I can hear a constant hiss. Oh, and when shutting the engine off I get a real long hiss.

Now you're probably wondering where these hisses are coming from. Well, it seems like they're somewhere in the ventilation system, like under the passenger side of the dash.

Would the vacuum check valve be part of this?

It's not just that I'm annoyed by the hissing, I have a wacko idle (though it's smooth and even with the AC compressor running) and sluggish throttle response.

Also, the car no longer starts the first time. When I crank it, it comes on, but it putters at about 200 rpm (or less) and applying the throttle makes no difference. Then, of course, it stalls after two or three seconds. After that it starts up fine.

I also think I've got IAC problems, but I've tried cleaning that thing twice already, with no improvement.

Guide me, oh wise ones...