Author Topic: '78 Qjet vacuum port  (Read 346 times)

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Offline skisix38off

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'78 Qjet vacuum port
« on: August 12, 2010, 09:02:19 AM »
on the passenger side of the carb, looking from the front of the car- just outboard of the idle mix screw is a vacuum port.  Mine doesn't ever show any vacuum on it- not at idle and not at part throttle.  What is this port for?

Also, while I'm asking questions...  I was reviewing some EGR stuff on my car and I noted that the secondary vacuum pot- the one that has the linkage to the secondary air flaps was staying closed, or in the position to NOT allow the secondary air flaps to open while I had the air cleaner off.  I don't ever recall that happening before with the air cleaner off.  It has vacuum to it and when I turn the engine off the valve releases but as soon as I turn the engine on the vacuum pulls it in and holds it.  It was 105 at my house yesterday and the engine was warm. 

While checking the EGR valve, I could put vacuum on it and have the valve actuate.  There was no idle speed difference between when the valve was open or closed( meaning when vacuum was applied= open and no vacuum= closed)  Is that right?  The manual says that idle speed should change.

I'm just trying to make sure my engine is running as good as it can....  Thanks for any help.

1978 Y88 L78 auto, PW