How do I mellow it?

[thehueypilot]

Maybe after sitting so long the carb has built up a varnish (or bug?) that is plugging some passages or a gasket dried out and cracked. Maybe a quick re-gasket is in order? I know when I put a carb into service after sitting a long time it usually has some issues with it that re-gasketing usually takes care of it.

 

[DarkBuddha]

Maybe after sitting so long the carb has built up a varnish (or bug?) that is plugging some passages or a gasket dried out and cracked. Maybe a quick re-gasket is in order? I know when I put a carb into service after sitting a long time it usually has some issues with it that re-gasketing usually takes care of it.

Actually the carb is brand new brand-new. We ordered it from Summit at the beginning of the month and just installed it last week when we replaced the entire fuel system.

 

[68converted]

Hey guy, I put the exact same carb on my 302 6 months before I did the conversion. I had the exact same problem and so I returned it to PepBoys. They gave me a replacement unit and that did it. No more rough idle. Never found out what was wrong with the first carb but just thought I would toss that out there. Good luck.

 

[mustangdave]

Check the contacts in that "new" cap and see if they are corroded. Also the rotor and where the plug wires attach to the cap.

 

[thehueypilot]

Actually the carb is brand new brand-new. We ordered it from Summit at the beginning of the month and just installed it last week when we replaced the entire fuel system.

You know Holley has never been known for very good quality and lately they have been back sliding badly. They have had a big turnover in Engineers over the years and some of them started Quickfuel which is just down the road from Holley. I found a double gasket under the power valve the last time I ordered a carb along with burrs that just about closed off some passages. You might want to take it apart just to double check it.

 

[BarnStang]

Some of those carbs sit on a shelf for a long time and the gaskets dry out. Ran into this on me Dad's FE motor. Got a rebuild kit and the idle problems cleared up. I am partial to the Edlebrock Performer. I gave up on Hollys...