For those equipped with Holleys: Help!

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Sep 29, 2009
Hipsterville, Brooklyn, NY
I've been having some issues with my Holley 350 cfm Model 2300 recently.

Frequent backfires, poor gas mileage, running too rich on idle, too lean on open throttle...all this pointed to a blown power valve. So I bought a two-stage power valve and replaced it, hoping all problems would be solved. False.

It was running richer than ever, even with mixture screws all the way lean. Blue smoke out the exhaust...

So I bought a rebuild kit. I replaced the seals, checked and calibrated the float level, and decided to take the two-stage power valve out and put in the normal power valve that comes with the kit. I got it to idle for a little while with the regular valve but nothing consistent, couldn't drive it.

So my problem is this: I've spent a bit on the power valve, rebuild kit, and other misc items for the carb and yet I'm in a worse state than I was before this little endeavor. It is my understanding power valves are interchangable. Am I missing something big here? Do I need to buy new jets for the new two-stage power valve?

Any input would be greatly appreciated.

Please explain in easy terms, this is my first carbureted vehicle...actually my first vehicle to begin with!

Thanks a bunch,

I have that same carb on mine and had some of those issues as well. One problem I found by accident was the adaptor plate was not tight on the intake manifold. The other thing is when I did some research about the power valve I discovered that I wasn't using the correct one for the amount of vacuum at idle I have. Bought a new one and that helped out a lot as well. I can't remember the simple formula for determining what power valve to use but there is a ton of information on the net about it. Invest in a vacuum gauge in is invaluable.
Your problem does sound 1,000 percent like a blown power valve. In the Chicago area you would probably never needed a high altitude (dual stage) power valve. Also, if you changed the Cam, your vacuum will also have changed, possibly requiring a power valve change. Good luck:beer:

do you have a picture of the way your holley looks on your motor? i have the same 2300 on mine and the throttle cable bracket is a total jerry rig, as is the spring that helps pull back the accelerator. its a random spring attached to the manifold- i sure would like to see a proper install of one of these models so i coreect mine.


Users who are viewing this thread

Top Bottom