[dana44]

Hi Smitty, welcome to the forum. First thing to do is verify the float level, it may be set too high. Second thing is fuel pressure itself, ensure it isn't above 4.5-6psi even though I think 7psi is max, no need to go that high with a carb. Third thing is the vents in the carb top, there may be a fuel return line that should be hooked up so expanding gasses have a place to go properly with the carb, and the last thing is make sure when she is warm that the choke isn't resetting itself automatically, they can if out of adjustment, to which flooring makes it open a little bit, above the flooded engine needing a fully open carb to clear when hot. These are all starters for problems with a carb, verify these most common things first.

 

[68RT]

You don't say which carb you have but most likely you are having "afterboil" from engine heat. That is controlled by a phenolic (Plastic) block under the carb. I am making the assumption tht you are running headers and do not have a manifold heat riser issue. Yes, high psi on the pump can cause some flooding issues or perhaps the needle valve is seeping just a bit. Where is the carb bowl vented too. Some have a vent that opens at idle. others just vent it to the venturi area. Knpowing which carb you have will help diagnose.

 

[stroudtom]

Best fix I did for my poly 318 and AFB was block the heat crossover but cold start up suffered a little.

 

[smitty14024]

Did I mention that when it comes to working with carbs I'm a total amateur? But at this late stage in my life I am ready to learn. The carb is also an Edelbrock Performer 600cfm with manual choke. I recently purchased a phenolic spacer but haven't installed it yet. I have also replaced the 383 cast iron exhaust manifolds with the higher rise 440's.

So, how do I check the fuel pressure?

 

[dana44]

Fuel pressure requires a fuel pressure gauge. Do a quick search for Edelbrock performer carburetor setting, get the settings for the float and do that first. You can also look at video to rebuild the carb, chances are good there are a couple on youtube. Edelbrock carb website has some good tuning information on it, too, always helps to understand how they work, which is a lot less complicated than than EFI and all its sensors.

 

[dana44]

I don't know your level of knowledge, but 383 and 440s (B and RB blocks) can only interchange the intake between these two engines in one case. Back in 1958 (I believe) was a 383RB block (early pre-440 block before the 413 and 426 Wedge). The only other part that does not exhange I can identify is the distributor (B and RB are different lengths). Your engine size is stamped on the pad located in one of two places. Flat pad on the block where the water pump and head intersect, driver's side, (B engine), or right of center looking at the engine where the valley pan under the intake manifold is, there is a flat bar with four bolts clamping the front of the pan, the RB stamp is there. The cast numbers on the side of the block can identify the engine, including the date the block itself was cast, so lots of info there. Hope it helps.

 

[storm9c1]

I agree with the phenolic carb spacer idea. But also be aware that Eddy carbs only want 6psi of pressure. No more. I had all sorts of problems using a stock fuel pump that I eventually bought the Eddy pump and had no problems ever since. Tee in a temporary fuel pressure gauge and see. Now this probably isn't the issue after letting it sit hot. That sounds more like heat soak boiling the fuel and causing the flooding. So I'd add the spacer first. I also blocked off the heat crossover on my 383 with a performance intake pan/gasket combo. My car no longer has the stock thermal choke (replaced with electric choke as is yours), or the heat stove setup, so I don't need it. Summer-only car.

 

[dana44]

That is something to think about. The intake, being aluminum, heats up faster and better than the cast iron ones. I think it is actually recommended to block off the heat passage in the heads (take a piece of the old pan and cut a square to cover, it is thin enough not to leak), something I always do because I port heads before I reinstall them, but even stock setups need less heat. Good call.

 

[acewiza]

Ethanol in the fuel is the root cause (afterboil).