My '01 Z28 6-speed has been idling higher and higher on cold-starts. It would hold about 1500 RPMs until I after coming to a stop for a few seconds, then it would drop down to ~800. Today it lit up the SES with a lean condition on both banks. I started poking around and found one of those tiny little plastic vacuum lines near the battery that was chewed/rotted and was hissing. I plugged the line, and the car runs AOK, but I can't figure out what isn't getting vacuum anymore.

It connects to a 3-way fitting (check valve?) right near the firewall. I have a picture of the line here (not sure if the HTML will work, but here goes):

<a href="http://photobucket.com" target="_blank"><img src="http://i208.photobucket.com/albums/bb105/ambidawn82/camaro/IMG_0837.jpg" border="0" alt="Photobucket"></a>

The line ran down the passenger fender (mostly inside the corrugated plastic) towards the battery. The loose end was very near the coolant overflow filler-neck. I cannot for the life of me find another end. The loom inside the corrugated plastic is taped solid in that area, and there doesn't seem to be anything vacuum-operated in the area.


As a side note, the AC always switches to the floor vents under heavy acceleration in 6th. I assumed it was just a lack of engine vacuum under the open-throttle condition, but I suppose it could be related.

 

If it is still there, look at the VECI label in the engine compartment, it shows the routing of all vacuum lines.

 

Why not just splice the broken vacuum tube back together with a little piece of rubber hose?
I may be going out on a limb here, but I'm willing to bet that GM put that vacuum line there for a reason.

 

But desn't the car always run better if you throw some of the factory stuff out? lol

 

Only if you throw out the unnecessary stuff. The trick is being able to tell which parts are needed, and which ones the factory needlessly threw in there just because they had the extra parts laying around. lol

 

This thread reminds me of my stepdad! He is about 70 and regardless of what he buys, the first thing he does is raise the hood and start ripping things out of the engine bay and throughing them on the ground, he even gets the plastic spoilers from under the front bumper because he says they cut down on gas mileage. I reckon he thinks every vehicle under the hood needs to look like a 69 Ford pickem up truck! Amazing the things still even start when he gets finished with them. LoL

 

The way I look at it, the factory wants to make as much money as possible when building a car, and I doubt very much they put in extra stuff just for grins & giggles. lol