Chevrolet  Forum - Chevy Enthusiasts Forums

Chevrolet Forum - Chevy Enthusiasts Forums (https://chevroletforum.com/forum/)
-   General Tech (https://chevroletforum.com/forum/general-tech-10/)
-   -   vacuum leak? (https://chevroletforum.com/forum/general-tech-10/vacuum-leak-51486/)

clintsy Jun 28, 2012 11:49 AM

vacuum leak?
 
So today my "double d' idle mixture tool arrived so i was tinkering with my screws this morning. The passenger idle screw was at 3.25 turns out while the driver side was 2.25 turns out so i thought 3.25 was too much so i evened both out to 2.25 which made it idle rough so i turned them both to 3.25 turns out and the idle speeded up and smoothed out..

The idle was @ 800RPM before adjustment and now it is @ 1000RPM which I know is pretty darn high so I go to adjust my curb idle screw and its not even touching the throttle plate which indicates the throttle plate is closed and the engine shouldn't run so I have a leak somewhere...is this correct?

And if i am correct ^ would this be a intake gasket leak or vacuum hose leak or what?


Bone stock 85 Impala with 83 E4ME quadrajet

clintsy Jun 28, 2012 12:03 PM

Forgot to say it has the 305 in it and I had a vacuum gauge hooked up and before adjustment it read a bouncy 18-19 inches and after a pretty steady 20 inches

kevinkpk Jun 28, 2012 2:28 PM

You should be around 19" hg at 700ish rpm. 1000 is too high, set the idle scew down till you get that. This will affect the vacuum. There is a fast idle screw that is probably your issue with trying to set the idle, can you post a pix of that side of the carb?

clintsy Jun 28, 2012 3:44 PM

I will post a few pics in a hour or so when my cam charges, when I loosen the curb idle screw it does not do anything. When I turn it in about 2 full turns the idle starts to rise.

Thanks for your reply
I'll post pics soon

clintsy Jun 28, 2012 8:54 PM

5 Attachment(s)
sorry it took so long i was waiting for the storm to pass..
i just took pics of the sides and the curb idle screw
i couldn't get the camera low enough to get a shot of the fast idle cam from the bottom

after i took the pics i started her to see if the idle was high,
it was pretty low in the beginning but right after i nudged the throttle a bit the rpm went back up to 1000 :(

clintsy Jun 28, 2012 10:31 PM

I also found a " remanufactured by Holley " sticker on the back of the carb if that means much ...

jwruss Jul 1, 2012 3:40 PM

from the second picture it looks like the fast idle cam is sticking. you can push down on the lever and it should release.

clintsy Jul 2, 2012 12:25 PM


Originally Posted by jwruss (Post 220079)
from the second picture it looks like the fast idle cam is sticking. you can push down on the lever and it should release.

The fast idle screw is turned out all the way so its not even touching the fast idle cam
Is it possible the fast idle cam itself is "sticky"?
The linkage on that side does seem a bit rusty

kevinkpk Jul 2, 2012 1:02 PM


Originally Posted by jwruss (Post 220079)
from the second picture it looks like the fast idle cam is sticking. you can push down on the lever and it should release.

X2, the idle set screw isn't even touching image 3. The fast idle rests on that cam, as posted pop the linkage to get the fast idle screw back, and resting on the cam.

kevinkpk Jul 2, 2012 1:03 PM


Originally Posted by clintsy (Post 219856)
I also found a " remanufactured by Holley " sticker on the back of the carb if that means much ...

Dosen't matter in this case if it's a holley or quad.


All times are GMT -5. The time now is 2:50 AM.


© 2026 MH Sub I, LLC dba Internet Brands