Can someone tell me what the ball near the fuel cannister is for? It has a vacuum line attached and it will not hold vacuum. Is it supposed to? I couldn't find it in the shop service manual.

 

It stores the vac so your cruise and HVAC don't drop out when engine manifold vac drops ; like when accelerating

 

So it should hold vacuum when applied directly to the top fitting? The cruise control fluctuates at cruising speed. Maybe that's the reason?
I wonder if I can remove it and seal the outside instead of replacing it?

Thanks

 

A line runs off the plenum through a check valve and splits. One goes through the firewall to the A/c , the other goes to the vac ball ,"T"-ing off to the cruise on the way.
If the ball is leaking then it would not be holding vac and possibly giving you a vac leak through the check valve into engine as well

 

Plug the line till you can replace. They are not expensive. A junkyard will have hundreds of them.

 

You can get them at Autozone. The nipple on mine broke when I tried pulling the vacuum line to do some vacuum checks. I think it was $15 and I say would be better than getting a 20 year old piece that has been laying in the junk yard.

I vacuum checked the Autozone one, and it held vacuum.

 

they should be the same as every other gm cars

 

Thank you very much for the info. Good to know something is available and reasonably priced.

I just finished removing the fuel rail and everything necessary to do it. Whew. That wasn't the easiest thing I've ever done. Most of the runner bolts were not tight at all. Some starting to come loose, but the engine produced good vacuum and spraying carb cleaner around all fitting/gaskets produced no rpm change.

The EGR valve takes over a second to move through it full travel. It checked out ok as far as holding vacuum and releasing it when starting the engine. I couldn't see if it was opening and closing when going from 2,000 rpm to idle.

I was also wondering how to check the EGR solenoid now that I have it off.

Dinner time! Have a good evening all.

 

http://members.shaw.ca/corvette86/EGR%20System.pdf

 

Thanks AGENT 86. It checked out fine with the key on, ground diagnostic terminal test.

I removed the vacuum ball (tank, reservoir, whatever) and held it under water. It does not leak. So I again applied vacuum with a hand pump that seems to not produce enough vacuum with a few pumps. However, if repeately pumped vacuum will come up to engine vac (10 pumps to get to 15) and the ball holds vacuum. So I think it's ok. Same with EGR valve. It takes about 4 pumps to get it to engine vacuum, which is actually it's entire travel, before it will hold vacuum. I don't think that's right, but will check a new one with the hand pump at AutoZoned out.

Now I'm looking for an air pump lower bracket/alternator bracket. This one was broken in several place before I loosened the first bolt. Removed it to get the valve cover off driver's side. Also loosened the A/C to move it forward enough to remove passenger valve cover and the rear EGR tube had to be removed to access rear inner driver side runner bolt. The runner bolts were a breeze after that using a 3/8 drive #40 torx and 3/8 6 inch extension, even on the rear driver side outer top bolt. Especially since most runner bolts were already loose!

Maybe some of this information will help someone else. Trouble with using any search feature, though, is knowing and trying various keywords. It takes the right keyword or valuable info is missed. And there is a lot of valuable info here, from past posts and members. Should I start a new thread including all the information gathered during this process?

Thank you! And thanks to Square for his excllent article and photos of an intake manifold install! http://members.***.net/effergyvette/...e_install.html