My car has been falling on it's face at times and I haven't been able to track it down. But today I found a vacuum leak and was wondering if it could be causing my problem. When I started the car up I could hear a sucking noise so I popped the hood. When I finally tracked it down I seen that the EVAP Vacuum line to the throttle body was what was making the noise. The end that connects to the throttle body was cracked and dry rotted. It's on there now and I'm going to order a new one regardless. But I am curious if this could possibly be my problem? Here are a couple of pics of what I'm talking about.

It is #5 on this exploded view.
http://shbox.com/1/1995_evap.jpg

And it is the top line coming from the solenoid in this pic. It is labled "To Throttle Body".
http://shbox.com/1/evap_sol.jpg

BTW,
I looked this part up on gmpartsdirect.com and they wanted about 5 dollars for the part and 49.75 for shipping. This thing is a plastic hose no longer than 8 inches. Hopefully it's not too much from the local dealer. Anyway, just though I'd throw that in there.

Thanks for the help everyone.

 

I doubt that is your problem. If its a sucking sound, i would check the PCV valve. It is on the drivers side of the intake manifold. Id pull it out and shake it. If it rattles, then thats not the problem. If you dont hear anything, then replace it. It is like a $3 part from autozone. The PCV connects to your crankcase at the front center of the intake manifold under the throttle body. That may be where the sound is comming from.

I wouldnt buy the GM part. It is just vacuum line, so go to an autoparts store and get about 3 inches. They usually give it to you for free when it is that small if the guys are cool.

-Stu

 

I know for sure that it is the EVAP hose that I am talking about. I pushed it on as best as I could (the hose is shot) and the noise quit. So it is for sure where the sound was coming from. As for the hose, it has 2 different size ends. The end going to the solenoid is rather small and the end going to the TB is quite a bit bigger. I was just going to use a piece of hose as well until I seen the difference in size. Thanks for the help.

 

you will be suprised how much a vacuum line can be expanded, just lube it up with some oil and you should slip it in. You could also get 2 different sizes and have the bigger one on the TB end and put the thinner one INSIDE the larger one, melt them together and use the smaller end.

That noise may or may not be the cause of your problem, but id tape it up with some duct tape, then drive around a little bit and see if it fixes your problem. EVAP i kinda weird like that.

 

You won't be able to expand this hose correctly, but if you pull that hose off, and tug on it, you'll see that the soft thick end will separate out of the hard line thin end. At least mine did. This two piece construction should allow you to piece together just the needed half of the hose -that is whichever half is the broken one.

Be careful not to break the thin line, it is pretty brittle.

 

Thanks guys. I appreciate the help.