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Gas shooting out vents and flooding engine

grasshopper

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Nov 13, 2015
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Location
florida
Ok like title says I have a 74 Charger with a 440 with a Holley 650 double pumper. When the engine gets hot it wants to flood out by pushing gas out the top vents. The car has a stock mechanical fuel pump with a Holley pressure regulator adjusted to 5 lbs. I am running 2 large inline filters. I have wrapped fuel lines with heat shielding material, and put a wooden spacer under carb. I also replaced the valley pan gasket with the Felpro one that blocks off exhaust crossover. I have removed the gas cap while ideling and it still floods out while hot. I'm out of ideas any help will be very appreciated, thanks. Oh and yes I have adjusted the floats many times even setting them a bit low,and even changed needle and seats.
 
Put a fuel pressure gauge after the pump to be absolutely sure its putting out 5 psi.
 
when was the carb rebuilt last,I bet the needles are gone with use of ethanol gas,mark
 
Keep the holley ... verify fuel pressure into carb, ditch the wood for an aluminum spacer, and I know you've checked but double checked needle and seat operation / adjustment ... need to figure out of fuel is venting due to over pressure or fuel boiling. can you keep your hand on the carb when the engine is warmed up or does it burn yor hand ?
 
I replaced needle and seats even though carb is only 2 years old. Fuel pump was putting out 11 psi that's why I installed regulator. Oh and forgot to add that I just took this carb off of my wife's 454 1970 monte carlo, and it worked perfectly on that engine. I only took it off because I put a 750 on the monte.
 
I'd put a gauge between the regulator and carb just to be positive it's really at 5psi. I'm running a factory replacement pump, and an in line gauge, 6.5psi unregulated output and no overflow
 
Im guessing its still putting out 11 psi, or close to it....
 
Yeah I have put two different gauges on the carb. Fuel line, and they both read the same.
 
Sounds like fuel presure is too high. My 650 dbl pumper works fine in all conditions.
 
I've always had good results with the DP Holleys. It's the spread bores and vac secondary carbs (except for the 3310) that gave me problems. If it was working well when you took it off the other car and now all of a sudden, it's not, I'm thinking something got in it. Had a similar problem and it turned out there as a piece of debris from a fuel line stuck in the needle/seat assembly. It didn't seem to be a problem until things were up to operating temps. Odd that it happened but......pull it apart and check things closely.
 
Check to see if your floats have a hole in them. They might be taking gas in and allowing the fuel level to rise up and blow fuel out the vents. Even the smallest hole will kill a float.
 
Check to see if your floats have a hole in them. They might be taking gas in and allowing the fuel level to rise up and blow fuel out the vents. Even the smallest hole will kill a float.
i agree i had the same type of issue after my carby was rebuild found out the new float had a hole dam Chinese junk replaced it with the original all good now no issues
 
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