Stock fuel pump to Holly? Thoughts?

[87Abe]

The truck was a mess of wires and clamps, I've change the manifold to a edelbrock 2101 4brl two hole plain and put the holly back on. It has a mini pump on it, but the stock pump is still good. When I run the stock pump, fuel comes out of the top slanted hole on the carb?. Is this because the pump or the carb? The truck was tbi.

Thanks again.

(I couldn't turn photos the right way. Sorry)

[87Abe]

more photos

[csdineley]

If your talking about the stock tbi in-tank fuel pump. It puts out too much pressure for a carb. Stock tbi pump puts out something around 12 psi. Your carb only needs 5-7 psi. Solution is to add a bypass fuel pressure regulator.

[87Abe]

Nice! Thanks for the info! I see they are under 100 bucks.

The holly is a dubble pumper and I wanted to hook up a switch to turn it off/on. So to save gas I'd leave it off then when I want to "kick it in the guts" I'll turn on the dubble pumper.

[MikeB]

Your Holley has dual fuel inlets, but also has vacuum secondaries, so it is not a double pumper. The secondaries will open only when "demand" is great enough. They are controlled by vacuum produced at a small port opening in one of the primary bores. The more the airflow through the primaries, the more vacuum on the port.

I just noticed your Holley is an old 4011 spread bore, designed to replace Q-jets back in the 80s-90s. It's quite a bit different externally from standard Holleys, but you can still get parts for it.

[87Abe]

Wow! Thanks fro all the info!!! I've been looking for some info on the carb for weeks.

I have a one inch riser in between the carb and manifold. I think my next step is to get a fuel regulator.

So having both fuel lines hook up wont make a real change in gas mileage?

[csdineley]

Nope

[geezer#99]

And that riser won't work with your new carb either. The carb will bolt on but you'll have a big vacuum leak. You need an adaptor plate like this.
http://www.summitracing.com/int/parts/sum-g1420

[87Abe]

Ordered it just now.