Car sits for a week Holley carb bowls are dry.

67-Beaumont · Veteran Member

Car sits for a week Holley carb bowls are dry.

4SPEED427 · A Poncho Legend!

Crazy as it sounds, sometimes a new fuel pump will cure that problem on a Quadrajet. I've had very few Holleys but maybe it's the same situation?

cdnpont · Canadian Poncho Superstar!

Show us what you have.

64PARCONUK · Addicted!

My Rochester does that almost overnight, even with a new fuel pump.

dualquadpete · Canadian Poncho Superstar!

are you running regular ethanol gas??? That "crap" evaporates fast and is a water magnet!! and will rot out any neoprene hoses and f/pump / carb diaphragms. Have also seen it rot out the fuel bowls on a Holley carb!!!!

cranks38 · Addicted!

dualquadpete wrote:
are you running regular ethanol gas??? That "crap" evaporates fast and is a water magnet!! and will rot out any neoprene hoses and f/pump / carb diaphragms. Have also seen it rot out the fuel bowls on a Holley carb!!!!

My thoughts, exactly!

I run nothing but pure gas in my carbureted stuff, from Holley to lawn mower. You might find this link useful - https://www.pure-gas.org/index.jsp?stateprov=BC

-- Edited by cranks38 on Sunday 15th of November 2020 11:03:43 AM

-- Edited by cranks38 on Sunday 15th of November 2020 11:04:15 AM

67-Beaumont · Veteran Member

Hello
Thanks for all the information
I am running Chevron 94 , As I said before it the first carb I have had that does this .
Maybe replacing the fuel pump may work . I see no leaks anywhere .
Thanks again .stay safe

64PARCONUK · Addicted!

Our base unleaded fuel contains 5% or less, it's 95 RON octane. We have a super unleaded (97) that contains no ethanol but it's even more expensive. High octane leaded fuel is still available to those who can afford it and know where to get it. I put 5 gallons (imperial) in every now and again for the sake of my valve seats, as I don't think any previous owner had them modified.

However, my carb has been running dry since before ethanol fuel was even thought of!

67-Beaumont · Veteran Member

Hello again,
Thanks again for all the great information
I did more investigation and found traces of fuel on the intake manifold
Remove carb filled it with fuel and put paper towel down under carb
Both bowl gaskets leaked down over a few days ,replace gaskets
No leaking now
Stay safe

65Camino · Uber Guru

Don't let it sit so they wont leak.

64PARCONUK · Addicted!

Just filled up my daily (blown, injected, quad cam, hemi V8 and British!) with an even higher octane Shell unleaded that we can now get. 99 RON.

I won't be doing that too often though, £1.30 per litre (CAN$2.26)......

cdnpont · Canadian Poncho Superstar!

Aviation fuel?

Magician40 · Poncho Master!

The term Percolation was always a problem with Quadrajets , a hot engine draws the fuel from the carb float bowls through vacuum draining the bowls.
Brian

64PARCONUK · Addicted!

Not aviation fuel as that still has to contain lead, so cannot be used in my "unleaded only" daily.

The 99 Shell product is available in virtually all of our Shell road stations.

I'm extremely lucky that I'm still "working" doing something I love and I do have access to avgas at work, which is £1.89 (CAN$3.29) per litre. Of course my 56 year old 283 would love some of that every now and again, but even mixing it with unleaded would be illegal, so I couldn't possibly consider doing that could I?

North · Guru

Europe uses RON octane (research) rating system and in North America we use PON (pump) rating system which is a average of RON and MON (motor). Bottom line is that on regular unleaded european rated 91 octane regular is the same actual octane as 87 here in North America. For super unleaded the difference is about 5-6 so 98-99 in europe is rated here at 92-94. Ethanol is less prevalent in europe but it's unfortunately spreading there as well.