hotrod351

something else you can try is, while idling, pop the spark plug wires of, at the cap, first loosen them, and when you pull the one that doesnt make a difference then you at least konw ehich cylinder is giving you the problem, plug, wire, valve, or what ever. thats how i found a miss in mine, turned out to be a valve in my case.

KBunny

I finally figured it out, there were two vacuum leaks. One vacuum leak, which I have taken care of, was a bad gasket between the carb and intake. The other vacuum leak, which I have not taken care of, is at the point that the shaft for the secondaries protrude from the passenger side of the carb. The car runs much better without any hesitation however the vacuum leak on the secondaries is noticeable at idle.

The prequel to the question is, I have rebuilt the stock 2 barrel carb on these mustangs before and that wasn't terribly difficult. I have done some basic work (jets and rods) on this carb (edelbrock 600cfm).

The question is, how do I fix this problem? is there an o-ring that I can just buy and replace or is there more to it? Thanks for your help so far.

109jb

A leak at the throttle shaft usually requires drilling out the bore that the shaft runs through and installing a bushing to restore the proper fit for the throttle shaft. It may also require a new throttle shaft, but usually a bushing will take care of it.

KBunny

Well that sucks (both literally and figuratively) I guess I will have to live with it for the time being then. Thanks for all of the help guys.

67mustang302

I wouldn't run with a vacuum leak, you can burn an engine down really quickly that way. And yeah, it'll require a more than standard rebuild to replace the bushing/shaft.

Just buy a Quick Fuel and be happy

KBunny

Well if thats the case then where can I get these parts needed to do the repair?

67mustang302

Contact Edelbrock, they should have the repair parts for it.

Adrenolin

Just as a note regarding the Edelbrock carb and fuel pressure since it was mentioned above. They really don't like more than 6psi and a number of issues can arise even at 6 to 7psi. I wound up installing THIS 4.5 - 9psi fuel pressure regulator and run at about 4.5psi.

I'm also running an electric Mallory fuel pump rated at 7psi however I've talked to a number of guys with the Edelbrock carbs who found 4.5 to 5psi helped.