When i bought my 87' S-10 Blazer the guy told me he had removed a vacuum line from the truck for his car.. So i get the truck started, and it idles at about 1500-2000 rpms. I've been looking for where he took the line out but i can find it and i asked him and he couldn't remember. so does anyone know where the line would be?? Any suggestions will be great..

 

Without a wild guess....

Just feel/look/listen around the intake for a vacuum leak or open vacuum port on the throttle body or intake.

From the sounds of it, you have a large leak that shouldn't be too difficult to locate.

 

I started up my blazer today. there is a noise behind the intake but i can't really see where it was suppose to be do you know any vacuum lines that are suppose to be back there?

 

I know this is a old post but i found the leak that was making the noise, it was a vacumm line that broke in half behind the throttle body that goes to the transfer case. I fixed it.. But the engine still idles at 1500-2000 rpm. I don't think you're able to adjust the idle on fuel injected right? any ideas anyone??

 

You can but it sounds like you have another issue. Might want to check the IAC and possibly replace.

 

Definitely sounds like you still have a rather large vacuum leak. I would start by disconnecting all of the vacuum lines to the engine and plugging them. See if the problem persists. This includes blocking off the line that runs to the brake booster.