72 Holley idle problem

[Gary S.]

Good afternoon to all. I am installing the restored and rebuilt original Holley in my 72 LT1. I have adjusted the floats and set the idle rpm but the engine rpm slowly drops off until it dies. This rebuild on this carb is a full teardown, replate, inspect, and reassemble with a test run on an engine. Unless I very lightly blip the throttle about every 30 seconds or so, the engine dies. It acts like air or fuel starvation but I am at a loss to figure this one out. If I set the idle screw in so that it idles at 1500 rpm, it will continue to idle. How flush should the butterfly plates be with the carb bore? I can't adjust the mixture screws because I need to keep working on the throttle cable to keep it running. I ran the car, as is, about three miles away to the gas station and it runs really strongly. In fact, this is the best this car has ever run in the four years I have owned it.

I know I haven't given you much to go on but I have exhausted my knowledge (limited as it may be). This rebuild was done by a very reputable builder known to many on this list. A call is in to him, also. Fwiw, when I first got the carb back, the front float was either out of adjustment (not likely) or there was something obstructing the needle. The site hole was way overfilled. I adjusted it down and drove the car. When I got back, the float was too low and I readjusted it back up to near where it had been before.

Do my symptoms sound like a float issue, mixture issue, or ???

Thank you,
Gary
72 LT1

[Gary S.]

never mind - found a stuck float

I just knew it had to be float related. I put the carb on and had to adjust the float two full turns clockwise to get the level down. Drove the car and had to adjust the float level 2+ full turns CCW and the fuel level in the sight hole still wasn't coming up. I pulled the front bowl and the float was stuck.

So my unlikely scenario turned out to be the issue.
Gary

[Chuck S.]

Reach For The Dale Pearman Special...

Tool for Holleys...A Louisville Slugger has good heft, but aluminum will work in a pinch. A nine iron should also work.

[Gary S.]

Re: Reach For The Dale Pearman Special...

Chuck, thank you for that memory jogger of Dale. I had forgotten that he had a passion for (against??) Holleys and he loved his Louisbille adjusting tool.
Gary

[Patrick H.]

Re: 72 Holley idle problem

"Do my symptoms sound like a float issue, mixture issue, or ???"

They sound like you could use a Rochester.

Patrick

[Gerard F.]

Re: Reach For The Dale Pearman Special...

Chuck,

Now imagine where Gary would have been with 3810 fuel bowls with no sight hole and non-externally adjustible floats. Hope your friend didn't go for them.

Jerry Fuccillo
#42179