need help. My 302 has recently developed the habit of running bad ALL the time. It has holley 600cfm, edelbrock air-gap, p+p heads, pop up pistons, headers, all that BS. When i bring it up to say, 2500 rpm in park, there is NO fuel coming out of the venturis. Is this normal, or do i need to go thru the carb to see whats up?

 

does it still run? It will only take as much fuel as it needs to run.

 

it still runs, but it fouls the 4 cylinders towards the front of the car, while the 4 in back run normal

 

Fouling the front 4 holes would not be the carb. When it runs on the primary barrels it will feed all cylinders. I would look at some
simple things like plug gap on the front 4,,,,Wires,,,Distributor cap.
I'm searching here?? Should not foul front 4.

 

Run worse at idle than at cruise? I,m guessing, maybe intake gasket bad, allowing crankcase fumes into cyl,s.

 

it runs equally bad at all rpm. when i drive it it sounds like misfire through the exhaust.

 

last time i had the front cylinders fouling it was a intake leak...

 

I hope its not an intake leak, i just rebuilt the engine 500 miles ago

 

this may or may not help but i just added a air gap and a eddelbrock 600 cfm on my 302 and it runs pretty bad on heavy rpms and i found out in my auto class that this could happen when your fuel pump is going bad, and im pretty sure thats the problem with mine i have yet to put it on, but everything else that could cause this prob is new on the 302 so maybe you should check out the fuel pump it wont hurt

good luck

 

Fouling on the front cylinders on both sides means that at least you know that both sides of the carb are doing it the same way. When you say that you don't see any fuel coming out of the boosters at 2,500 rpm. Do you mean that there is nothing, or only a little drip. Did there used to be fuel coming out at same rpm's? If you are fouling the front 4 cylinders I would suspect a vacuum leak at the rear of the carb or plenum.
As far as the fuel, the engine at low power requirements can run up to about 3K rpm before making it out of the transition circuit and into the main jets. The transition circuits are the long holes just above where the idle mixture screws let fuel into the bottom of the carb. They run vertically and should be about 1/8 to 3/16's inch long. Just because you are reaching a certain rpm doesn't mean that the engine needs a lot of air. If the throttle blades are not past the transition slots then you will pull virtually no fuel through the main metering jets.
Are the rear butterflys closed all the way on the carb? I believe there is a screw or a tab that you can adjust to open them up.
A vacuum leak can cause the misfire sound and cause all sorts of strange things.
What kind of distributor and ignition are you running. Is everything in reasonably good shape?
On certain engines there is a tendency for one end or the other to receive more fuel than the other. Since edelbrock is a very good manifold manufacturer I don't think it would be manifold design. Did you call Edelbrock and ask them? They might have had similar problems and know exactly what to test.

Are you sure that the fouling is coming from fuel? Is there black smoke at the exhaust? What kind of fuel pressure are you running? If the front float is messing up it will run down the venturi and go toward the lowest portion of the manifold. Is the power valve blown? Test it by taking it out and sucking on it, you shouldn't be able to suck air from one side to the other.

Many questions and many possible answers. It might be a bad combination of several of the above things. Trial and error is where you have to start. If you go through all the obvious things and get no results come back here and put up what you found. Maybe somebody else will have an idea.

 

I went through the ignition, and checked the compression, all seemed good. I took the carb apart and cleaned out all the passages, and put that all back together. Then i checked for dead cylinders by pulling off the plug wires 1 by 1 while the engine was running. #6 cyl. was dead. I changed the spark plug, and it ran nice and smooth. As for the fouling of the front, i never determined what that was. Anyone have any suggestions for what plugs to use? Thanks for all the help, i learned some new stuff, PEACE OUT!

 

What intake manifold are you using..?

If you are using a single plain manifold with a holley carb i'd lean toward the front metering plate gasket being cracked or torn...

It happened to me.

FORD

 

One other thought.

If your using the stock dual plane intake. I had a friend that his engine was missing on number 1,3,6 & 8 plugs...

His Holley base plate was cracket on the rear throttle shaft, on the right side... use WD40 while engine is running , spray it all around bottum of carb, if engine idles up, you've found the leak.