All Small Six Help! Did I just screw up my new build?

[awasson]

Willingnesslimp,
I just noticed that you are running a regulator with a pressure gauge before the carburetor. The way it looks is it’s plumbed as a dead head system (without a return line). Such a system will not work with your Weber carburetor that has a mechanical fuel pump.

My recommendation is start with a facet electric fuel pump and keep the regulator as it is.

If that doesn’t work, then I would recommend replacing the regulator with one that will allow a return to the tank.

I doubt that's the issue. The only difference he has vs mine is that his pressure gauge is in series with the carb and mine is on the gauge. I'm not crazy about the mechanical pump because it can/will heat soak and boil the modern fuel we use but aside from that, I've had no issues with mine and it's pretty close in all aspects.

I think the carb is dumping fuel.

 

[vssman]

Willingnesslimp,
I just noticed that you are running a regulator with a pressure gauge before the carburetor. The way it looks is it’s plumbed as a dead head system (without a return line). Such a system will not work with your Weber carburetor that has a mechanical fuel pump.

My recommendation is start with a facet electric fuel pump and keep the regulator as it is.

Here is a fuel pump that should work deadhead with your regulator.

Facet Cube 12v Fuel Pump, 1/8 NPT, 2.0-4.5 psi, Stainless | Pegasus Auto Racing Supplies

Come check out our Facet Cube 12v Fuel Pump, 1/8 NPT, 2.0-4.5 psi, Stainless at Pegasus Auto Racing.

www.pegasusautoracing.com

If that doesn’t work, then I would recommend replacing the regulator with one that will allow a return to the tank.

I run a Holley low pressure (1-4psi) regulator w/o a return along with a mechanical pump on my Webers without issue. It’s been that way since 2008.

 

[63 Sprint]

awasson and vssman,
I understand that your fuel systems are working properly. Unfortunately, this doesn’t mean that Willingnesslimp‘s setup will be functioning the same. As we all know, fuel pumps have been a crap shoot lately. I’ve seen how bad mechanical fuel pump pressure can pulsate on a single stage regulator. This is usually eliminated when using a return. I’ve seen the Holley 12-881 regulator (with return) buffer out pressure impulses on a dying electric fuel pump.

I personally have great success with the single stage Holley Regulators with a return. They are simple, inexpensive, easy to get and they work.

Just to let others know, the Holley 12-881 regulator with return that I have can be turned down to 2 psi. I tested it because at one time I was thinking of using a Weber 32/36 on a 240. There was no fluctuations at all. And the 300 was still able to drive around with 2 psi feeding into a Holley 390 while driving around town. I didn’t push it though.

It could very well boil down to the carburetor having a piece of debris, stuck in the needle seat. Or, something else. I’m just being honest with my years of working with mechanical pumps. At one time they were reliable. Lately, I will not trust them. In other words, these days, I hate mechanical fuel pumps. A good and properly installed electric fuel pump is proven to be much more reliable and accurate on fuel delivery than most of today’s mechanical pumps. I personally will not trust any of todays aftermarket mechanical pumps on any of my vehicles.

It could be something as simple as the Weber float is out of adjustment. Unfortunately, their are times that I will take it for granted that the float level was already checked before the carburetor was installed.

What ever the issue is, it has to be something simple. Everything that has been shared today, should help with figuring out what is happening. I hope that this issue will be resolved soon.