Fuel Vaporization Using Eddy Carb -- In-Line Fuel Pump Question

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cudaracer

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A while back someone gave me what I thought was good advice on curing my fuel vaporization issue with my 318 build and Eddie 600 carb, but I searched and could not find it. Or perhaps I recalled it incorrectly. So I have been wearing out my starter motor every single time I turn off my engine hot, and it sits long enough to vaporize the fuel out of that crappy carb. I then crank it for about 5 seconds, which is embarrassing. My options and successes thus far are:

1. Composite spacer under carb. Did that, does almost nothing.
2. New carb. This is my 2nd choice, based on price. But how certain will I be that I will cure the problem.
3. Electric fuel pump system to replace mechanical. Last choice. Very expensive.
4. In-line fuel pump to system to supplement mechanical. 1st choice, based on price.

All suggestions and tips and specifics are appreciated, especially if they are backed by experience that you can elaborate a bit on.
 
Double check your float level and fuel pressure. If you have more than 5.5 psi at the carb (or so), it won't like it. Float level should be at 7/16".

If it does boil over hot, slowly push the accelerator to the floor and then crank the engine until it fires. It will save your starter by unloading the choke and clearing out the overly rich mixture faster. Edelbrocks seem to be known for tougher hot starts, but modern gas doesn't help any. I think you should expect a little bit of hard hot starting these days; all of my cars do that now to some extent.
 
For $50 bucks you can get these mini electric fuel pumps as a booster to your mechanical pump. Mr.Gasket,K&N and others(They are the same pump just different names).I have that problem with my old cars with summertime temps round here at 90's to 120 degrees.Mount as close to the tank,on a switch.I turn it on before starting to prime the carb and turn it off after it starts.Also switch it on when running the car hard.They come in 2 pressures 1 to 2 psi and 4 to 7 psi.the 1 to 2 psi has a anti siphon valve that is really restrictive in my book when not running it. The 4 to 7 psi does not have the valve. Yes I got them both to test and the 4 to 7 psi is my choice. They also come with a filter. Not bad for $50.
 
I forgot to say that I ran the 1 to 2 psi on a 79 Chrysler 300 E-58 360 with a stock Thermoquad and without the mechanical pump as a test. Damn thing drove just fine.I was looking for a problem that turned out to be in the ignition.
 
It could be a cool 50 deg day, does not matter. The heat from the engine radiating up far exceeds outside temps.

Also, I was thinking to mount it just upstream of filter, which is just upstream of mechanical pump, and wire it to ignition switch. My thinking is, turn on ignition, pause for a moment, then start. Anything wrong with this setup?
 
cudaracer said:
OK, so I am leaning hard toward this Demon 625 carb with composite bowls, to cure both my horrible off idle hesitation and fuel vaporization issues.

Thoughts?

http://www.summitracing.com/parts/dem-1901
Click to expand...

Believe me, nothing is going to totally eliminate that problem except a carb change.
Electric pumps, anti siphon, regulators, spacers, non of it.
There are only two things that really help, and those are a spacer and a return fuel system and they only solve some of it.
Holleys don't have this same problem due to the bowls being out away from the intake farther so they don't get as hot.
The Demon is almost exactly the same design so it should cure it.

Sure some will say "I used a thick spacer and cured it" or "put a return system on it" but this conversation has been going on for years and I have yet to see a solution that works for all of us.

That Demon carb is close to the same design as the Eddies fuel bowl wise, but the composite body may be a big help.
I would still use an insulating spacer even with that carb if I could.
 
TrailBeast said:
Believe me, nothing is going to totally eliminate that problem except a carb change.
Electric pumps, anti siphon, regulators, spacers, non of it.
There are only two things that really help, and those are a spacer and a return fuel system and they only solve some of it.
Holleys don't have this same problem due to the bowls being out away from the intake farther so they don't get as hot.
The Demon is almost exactly the same design so it should cure it.

Sure some will say "I used a thick spacer and cured it" or "put a return system on it" but this conversation has been going on for years and I have yet to see a solution that works for all of us.

That Demon carb is close to the same design as the Eddies fuel bowl wise, but the composite body may be a big help.
I would still use an insulating spacer even with that carb if I could.
Click to expand...

Wait, so Demon is too close to Eddie?
What carb do you recommend?
 
Demon makes 2 styles of carb now, the Holley copy and the Carter copy. I don't think anyone trying to follow this discussion knows which type Demon you are talking about.
 
cudaracer said:
Wait, so Demon is too close to Eddie?
What carb do you recommend?
Click to expand...

69_340_GTS said:
Demon makes 2 styles of carb now, the Holley copy and the Carter copy. I don't think anyone trying to follow this discussion knows which type Demon you are talking about.
Click to expand...

I went to the link address and saw the one he is looking at.
The design is close to Edelbrock in that the bowls are within the square area right above the intake mounting just like an Eddie, but the composite body could only help.

The original Holley design is way better about fuel boiling because the bowls are hanging out there in the air.
 
What helped me "before" I went EFI. That in itself is a convoluted story LOL

Carb spacer as mentioned.

Consider blocking the heat crossovers or even going to an air gap manifold (I did not)

Pay considerable attention to fuel line routing and you can buy insulation sleeving (ceramic) if needed)

As mentioned rear mount pump. However pay attention to pressure. You don't want excessive pressure blowing past the needles

LAST and THIS IS quite effictive.........Construct yourself a fuel return system. Wix makes fuel filters with built in vapor return orifices. 33040 (5/16) or 33041 (3/8) filters have a built in 1/4" fitting with a return orifice

You will of course have to 'string' a second line back to the tank and devise a return into the tank. A few ways to do this.

Also, engine problems causing borderline high running temps, take a good look at that.


In the meantime a "stop gap" work around.....put an accessible toggle to turn off the pump. As you idle into a parking spot, learn to anticipate your short term run time and turn off the pump to run some fuel out of the carb.
 
There is a simple fuel filter with a return nipple already on it. Chrysler has em but there are generic versions as well.

Just run a line back to the tank as mentioned above. It's probably the #1 modification to make before you start spending money on everything else. You can modify your sending unit to have another nipple for the dump line or buy a new sending unit that already has it. The return line allows the vapor pressure to bleed off thus allowing liquid fuel to move in the line.

Many people on this site have done it and swear by it including myself. If you still have issues then move on to spacers then electric fuel pumps, etc. Try to buy the best gas you can find in your area and stay away from Eth.

Good luck.

Mop
 

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can the vapors be routed right to the vacuum canister, which is already about 10 inches away?

Or is that a dumb question :(
 
Here is a two step fix for this and any other Edelbrock carb problem -

Step One - unbolt Edelbrock carb
Step Two - bolt on Holley carb

Problem solved.

I fought and fought and fought with my Edelbrock carb 20+ years ago. I was determined to run it because I had problems with my first Holley (blown out power valves, dirt,etc.) and also my then co-worker told kept telling me it was junk. It made me more determined to run it.

Holley fixed the power valve issue years ago. The dirt issue is easily prevented with two filters.

What made me change my mind? The constant issues like the OP is having, PLUS the final straw, which was that a 5.0 Mustang blew my doors off getting on the freeway.

I ditched the Edelbrock and bought a brand-new Holley 650 DP. The transformation was amazing! Picked up .22 and 4 MPH in the 1/4 mile. Plus, no more hot start issues. That car would start with barely a tickle of the key even after sitting a few minutes when hot.

I hate to see guys banging their heads against the wall with these POS Edelbrock carbs. You are leaving HP on the table and subjecting yourself to unnecessary pain and suffering. Make the jump to Holley! You won't regret it!
 
with a mechanical pump, filter should be downstream of pump, like mopar did factory. how hot does the engine run? I run an old carter avs and a 1/4" thick edelbrock gasket and blocked heat crossover with no problems
 
Marcohotrod said:
with a mechanical pump, filter should be downstream of pump, like mopar did factory. how hot does the engine run? I run an old carter avs and a 1/4" thick edelbrock gasket and blocked heat crossover with no problems
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Temps seem OK, I have a good radiator with shroud and clutched fan, low CR engine, spacer plate under the POS eddie, heat cross over blocked, new mechanical pump, and a clear plastic fuel filter upstream of pump, not downstream. About 6" upstream between tank and pump. I was told that is what I should have.
 
cudaracer said:
can the vapors be routed right to the vacuum canister, which is already about 10 inches away?

Or is that a dumb question :(
Click to expand...

No.

Not a dumb question but think about it for a minute. That vapor will eventually turn back into liquid. That liquid is gasoline. The best place to store unused gasoline in a car is the gas tank. :D
 
clear plastic fuel filter upstream....


Can you say fire in the hole?


Take a break from your frustration and try the cheap and easy way. Simple filter will do wonders for your car.
 
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