Just installed one of Pony carbs restoration jobs of my 4180 holley off my 84 mustang gt. When I shut the engine off, fuel seeps out between the throttle body and heat shield. Pony said my needle and seat was stuck but all attempts to fix did nothing. Mailed the carb back to pony, they cleaned and test ran it. I reinstalled the carb and it stills leaks fuel on the right front side all over the heat shield. Any help please cause Pony is not helping. I'm $1000 into 2 rebuilds now and the car still runs rich plus the fuel leak problems.

 

Pictures of where it's leaking from? After you shut it off can you see fuel dripping from the boosters inside the carb?

 

I can't take a picture but the fuel is mostly on the right side and pools up on the heat shield. When I look down inside the carb there is some fuel on the throttle plate. After the car sits, its very hard to start. Its almost like the front bowl needs to refill cause it all leaked out or its flooded.

 

Probably the other way around. Float level to high or dirt in the needle valve is causing fuel to drip into the intake and flooding it.

 

first off is this the holley that came stock with the 84 because all they do is leak fuel and cause problems best thing you can do is get a new holley. it does sound like your float level is a little hight and its easy enough to adjust yourself.

another note i completely forgot they had heat shields that was one of the first things to go on mine lol

 

Ok, one item, the Holley 4180 was also used on the pickup 351HO and 460 engines. The leak, if it is on the secondary throttle plates is probably a warped metering body on the secondary side. Common problem caused by the use of "pot metal" (zinc alloy) castings and high underhood temperatures. The absolute worst were the Chrysler big block (383-440) engines from the late 60s/early 70s. At one time Holley made a modification kit for them that reversed the gasket sequence on the rear, but it had a special seperator plate that went all the way to the edge. I used to own a carburetor shop, so I got real familiar with them. Maybe Pony carbs isn't aware of this fix, I scrounged one for my 86 F350 to cure the problem.

 

adjust the float leval and check the needle and seat again

 

Thanks for all the good advice. I adjusted the front float and that seemed to stop the leak. I'm still not happy with how rich the carb is (very strong exhaust odor in the garage when engine on). It still seams very hard to start cold or hot like its flooded or taking a long time to get fuel back into the bowl. Question, what carb will bolt directly to the stock manifold and pass these retarded emission laws in Phoenix.

 

I have the holley 80457 600 cfm carb on mine. I just left the lines for the bowl vents running up under the aircleaner. Cant tell they arent hooked up. As long as you have the air pump, cats and charcoal cannisters you should be good to go.

 

Running rich and hard to start like no fuel, could be bad or improperly installed power valve. If you can't lean the mixture enough at idle to run right (emission engine should be lean anyway) then power valve is the culprit. The power valve has been the Holley curse forever.