Edelbrock Carb dripping fuel in after shut down..

[RustyRatRod]

It is not the ethanol in pump fuel causing the issues. Once the rubber lines, seals and gaskets were redesigned to be compatible with ethanol all those issues stopped.

The biggest cause of this is the lower Reid Vapor Pressure. Pump gas is blended for EFI, not a carb.
EFI is a closed system and a carb requires atmospheric pressure to function. On shut down the residual heat in the engine goes up and the fuel boils off. It has nowhere to go except out the boosters and vents. Ethanol free “clear” pump gas does the same thing and there isn’t any ethanol in that.

The other issue is the aeromatics used in “modern” pump gas. Xylene, benzene and toluene are three I can remember and they contribute to the ills we get with “modern” pump fuels.

I’m not saying to not use a return line. Im saying it’s not ethanol causing the issues.

But if the fuel is cooler to begin with BECAUSE you are running a return, then it "might" just cure the boiling off from the residual heat after the engine is cut off, right? I think what Steve is trying to say is, we need all the help we can get with ethanol laced fuel and I agree with him. Evidently, so did Chrysler.

 

[RustyRatRod]

Never had these issues before unleaded or mixed fuels in the late 70's . Been putting returns on since and solved many carb rich problems. I am not a chemist so I always call it ethanol type fuel. We use to call it corn gas back in the day. But what I can tell you is my Duster had the same issue with 114 and 116 race fuel. That is why I spent the $500 for what I needed to run a return. Big difference when going round after round with no cool can or on the street.

I would always have to start the car and turn the pump off and on until cool fuel got to the carb until it would idle, before the return was installed. Take it to the drive in up the street and it would not restart without doing that .

After the return was installed it never did that again and the car ran leaner that I had to put smaller low speed air bleeds in the carb. Yes we had rich lean gauges in each bank.

I remember and I know you do too when they called it "gasohol". lol

 

[Newbomb Turk]

But if the fuel is cooler to begin with BECAUSE you are running a return, then it "might" just cure the boiling off from the residual heat after the engine is cut off, right? I think what Steve is trying to say is, we need all the help we can get with ethanol laced fuel and I agree with him. Evidently, so did Chrysler.

I was agreeing with Steve too. Just not the ethanol part.

 

[mopar head]

1/2" phenolic spacer and Holley carbs= no problem

 

[Ricks70Duster340]

Put a return filter on it. You are dead ending pressure on the needle and seat. When fuel boils the float sinks and in come the fuel. Restart is flood city without a return filter.

With an electric pump you need a bypass regulator.

View attachment 1716455946

View attachment 1716455947

View attachment 1716455948

I use -6AN line from the fuel pump to the carb. What is the best way to stay with that type of fuel line and incorporate the fuel separator you show?

 

[TT5.9mag]

I live in California with arguably the worst fuel in the nation, laced with ethanol, and a bunch of other crap. It’s hotter than hell, and humid (currently) (so the worst scenario possible) and I run an edlebrock mechanical pump deadheaded into a Holley carb. Zero problems. Starts hot/cold doesn’t leak, doesn’t dribble, doesn’t load up, no return line. Maybe I’m lucky.

 

[TT5.9mag]

@TF360 whats the fuel pressure while running? And what are the floats set to?

 

[RustyRatRod]

I was agreeing with Steve too. Just not the ethanol part.

Well then act like it, cause you're actin like a dang hard head.

 

[Oldmanmopar]

I use -6AN line from the fuel pump to the carb. What is the best way to stay with that type of fuel line and incorporate the fuel separator you show?

I used a bypass regulator and ran another braided line back to the tank my electric pump was mounted in the rear of the car and the tank had a dual outlet sump.

Or you can try this from speedway motors with a manual pump.

click on this Robot or human?


Robot or human?

 

[Newbomb Turk]

I remember and I know you do too when they called it "gasohol". lol

Well then act like it, cause you're actin like a dang hard head.

You need to read post 21.

 

[fishmens67]

I remember and I know you do too when they called it "gasohol". lol

I do and I remember having to jet up .

 

[CRUZE 418]

So replacing our orginal fuel sending units that work for a new sending unit that doesn't work so that we can have a fuel return line? That would be the case for a non return sending unit. I don't disagree with the return line, but I am not doing the meter match thing.

 

[Two7T3Dart]

If you have no pressure behind the needle after the pump is not pumping how can it push past the needle. Your not thinking with your dip stick.

Have you never tried removing the fuel line from the carb right after shutting off the engine? There's still fuel pressure there, so it can blow past the needle and seat and flood the bowl.

 

[mopar head]

There's still fuel pressure there,

Yup, inline gauge will show that, with a tight system it`ll take many hours for pressure to bleed down.

 

[Patosmith]

Just check the easy stuff first. Float level, Crap in the needle / seat.
You say it's a new carb. I kinda doubt the floats leak and sink. Not saying they don't but wouldn't be on the top of my list.
I run carbs without return lines on both of my hotrods. I have a 72 Challenger with a 505 big block with a single Holley carb. No issues. My 56 Chevy has a 671 blower and 2 Holley carbs. No issues. Both have mechanical fuel pumps.

 

[TF360]

Talked to Edelbrock and they are going to take it back under warranty, so I'll send it back and let them fix it. It's really brand new. We'll see how the process works