I have a Holley 4548-S carb, Ford  P/N D0PF-9510-U giving me problems.  Drove 250+ miles on Thursday, climbing 3500 ft in the 30 miles, no problem. Drove around at 4000 ft. for a couple of days, maybe 75 miles, no problem.  Went to leave this morning, and the car wouldn't idle.  Stopped for gas at about 100 miles, engine temp about 180 still wouldn't idle.  Stopped for lunch at about 180 miles, in neutral at a fast idle, maybe 1200 RPM the engine would surge regularly, my wife thought I was moving the throttle to keep it running.  Engine temp close to 200, ambient temp around 90.  Finally got home and backed in the garage and could smell what seemed like a rich mixture.  The whole time it seemed to run well at highway speeds, 65-70 or so, though I might have felt a little surge.

After the engine cooled, I decided to check float levels, gas didn't pour out the check screws, but would splash out a little for the few seconds it tried to idle.  One thing that caught my eye was the fuel bowl was almost empty before I started it, though it did fill right up.  The more troubling thing is on the rear bowl where the fuel delivery tube enters there is a fuel leak, not the o-ring on the tube, but on the side where there looks to be a pressed in plug, it's leaking around the plug.  I've had a fair amount of experience with Holley 600s which are very similar, but haven't seen this leak before, and it doesn't seem to be something that would affect idle.

Any thoughts or help would be appreciated.

Thanks,
Don