On initial start up of my 1968 buick riviera 430-4 everything is in high idle and fine. But after letting it warm up the idle starts to just scream and I can hear knocking in the engine. After hearing it I can throw it in drive and the idle goes down but when back in park it's that same way too high idle. How do I adjust the idle to remain smooth even at high idle? And is there another problem causing the knocking? Thanks
Does the carb have a choke? And do you have a tach to see what rpm its running at? wait for others to chime in but answering those two questions might give some more needed info..
The high idle is likely related to a choke issue. It will require an adjustment or parts or perhaps both. Listen to the knocking from the bottom of the car. See if it is coming from the bottom of the engine versus the top. If the engine has never been rebuilt, this could be a bearing issue.
So you are saying that when you first start the engine, the choke engages, and you have a fast idle, but when it warms up, the idle speed increases even more? And this knock, is it a deep knock, or tapping from the valve covers? Is the knock rhythmical, or does it come and go?
It does have a choke but it's a manual and when I start it I engage it then let it go. The knocking sounds pretty light but from the passenger side valve covers and most of the time I don't notice it. It just sounds like my air cleaner is bouncing around. I don't have a tach for it.... Yet. Thanks for the replies keep them coming ---------- Post added at 09:35 PM ---------- Previous post was at 09:34 PM ---------- Oh and the knocking comes in goes. Is a valve hanging?
